Hoppip can be found on Routes 32 and 33 during the morning and the daytime, but not at night; it can also be found on Route 48 at any given time of the day. Skiploom can be found on Route 14 during the morning and the daytime, as well as the Meadow area of the Safari Zone, whereas Jumpluff can be caught in the Marshland area.
The Hoppip line has five weaknesses, one of which is double, and essentially all of them are a common sight in Johto. It is painful to train, learning the first offensive move only at level 10, and essentially no good STAB whatsoever until Giga Drain, as well as no reliable Flying moves. Then why use it? The answer is simple: fun! Jumpluff is a really non-traditional nuzlocke Pokémon, in that its best (and essentially only) option is to run a Leech Seed-based set, which makes it a very passive, slow-killing Pokémon. It is definitely not the kind of Pokémon an inexperienced nuzlocker should use, nor anybody who wants an easy ride in Johto. However, its unconventional ways can make it a very amusing team addition for more experienced players, and even this seemingly harmless cotton ball has a trick or two up its imaginary sleeve.
Proton (Slowpoke Well): Hoppip can hope to defeat Zubat by using Stun Spore (if it already has it) and then spamming Tackle and Synthesis until it goes down. However, it should by any and all means avoid Koffing and its Smog.
Gym #2 - Bugsy (Azalea Town, Bug-type): Hoppip can only realistically hope to defeat Metapod, and it will still be tough, as its Shed Skin will repeatedly heal it from PoisonPowder and it will likely shrug off Tackle; Kakuna has Poison Sting, which is more threatening than Hoppip's best move and can even inflict poisoning. Skiploom has better stats, and therefore better chances; it can defeat Kakuna without too much trouble, though it could still get poisoned in the process, which would make it need some healing. Metapod is easier to beat with Skiploom, as well. Scyther can be put to sleep and then Tackle-spammed, with Synthesis or healing items support, as its U-turn is still dangerous even without the weakness: a critical hit is likely one-shot Skiploom from full health, and from two Leers onwards, critical hits are not even needed to kill.
Rival (Azalea Town): Do not attempt to fight Gastly, it has Mean Look and Curse and Skiploom is completely powerless against it. Zubat is more manageable, though it will still be annoying with its Supersonic and Bite, which deals about as much damage as Skiploom's Tackle. Quilava is to be avoided for obvious reasons; Croconaw will also deal considerable damage, 3-4HKOing with Bite, but can be stalled with a combination of Stun Spore and Synthesis. Likewise for Bayleef which, however, is best dealt with through PoisonPowder, as it has PoisonPowder itself and Tackle will not do a lot of damage to it, especially if it puts up Reflect.
Gym #3 - Whitney (Goldenrod City, Normal-type): As Leech Seed access would require overgrinding, the best option for Skiploom here is running a set with Protect in it, and also Synthesis for players with healing limits. The rest of the strategy can go two ways; one way is stalling with Stun Spore and Headbutt, hoping to get the flinch as often and possible, and using Protect if Miltank happens to Rollout, so that the damage stops stacking up; Sleep Powder can work just fine as well, and makes Protect marginally less necessary, though its 75% accuracy and Skiploom's lower Speed still mean that Miltank might get two or even three Rollouts in before Skiploom manages to put it to sleep, or put it to sleep again. A safer technique involves setting up Swords Dances against Clefairy, praying that it does not Metronome a Blizzard, and healing as necessary until Skiploom reaches maximum Attack; that will allow it to 3HKO Miltank with Headbutt, and Miltank will not one-shot Skiploom from full health no matter the move: even a critical Stomp cannot kill it. This strategy still requires Stun Spore, as its Stomp is close to a 2HKO and Miltank will still win if faster, replenishing its health with Milk Drink. As for Clefairy, three moves are certain to kill Skiploom from full health: the aforementioned Blizzard, Selfdestruct and Explosion. If its Metronome does not copy any of them, Skiploom will win.
Rival (Burned Tower): Once again, Gastly should be avoided, as Skiploom's best weapon against it is the resisted and low-power Bullet Seed, which can do very little against Mean Look and Curse. Zubat is also a threat now, as it has Wing Attack; avoid it, as it easily 2HKOs Skiploom, who can 3HKO it at best. Magnemite could be defeated with Sleep Powder or Stun Spore and the usual stall techniques, though its high Defense and resistance mean it would take long and probably be more trouble than it is worth, especially since it carries SonicBoom; Quilava is a no like before, Croconaw is even worse than Quilava due to now having Ice Fang, and Bayleef is likely the only manageable starter Pokémon, whose only offensive move is the doubly resisted Magical Leaf. Unless the starter picked was Totodile, it is best to keep Skiploom out of this battle altogether.
Gym #4 - Morty (Ecruteak City, Ghost-type): Do not try this with Skiploom, or even Jumpluff, assuming it has already evolved. They are both equally helpless in this battle, with Bullet Seed being the "best" possible move both of them can rely on, while the ghosts have either the Mean Look and Curse combo, or Hypnosis and Dream Eater (and the scary Shadow Ball, in Gengar's case). An already evolved Jumpluff with Substitute may have chances against the level 21 Haunter if it outspeeds, puts the ghost to sleep and then sets up the sub and keeps it throughout the fight, but Curse will still be an issue and even the possibility is not enough to make it worth the trouble, when there are so many Pokémon that could do a better job in this gym.
Eusine (Cianwood City): Drowzee should not be much trouble unless it lands Hypnosis and starts using Dream Eater, and even then, Awakenings will provide a fix. Haunter is dangerous for both Skiploom and Jumpluff, for the same reasons as the Morty battle: there is no way it can be hit for enough damage before it Curse-traps. Electrode's STAB Thunder is no joke either, and Skiploom should avoid it altogether; Jumpluff has slightly better chances, and while it will very likely be outsped, it can use Sleep Powder or Stun Spore and then spam either Leech Seed and Substitute or its best offensive move, until Electrode goes down. Critical hits are a risk, but Jumpluff's bulk is sufficient to handle one at full health, as Thunder just barely fails to 2HKO.
Gym #5 - Chuck (Cianwood City, Fighting-type): Primeape's Rock Slide is more trouble than it is worth, especially as Jumpluff lacks the necessary Flying STAB to deal enough damage to it; it could paralyse it with Stun Spore and then stall with Headbutt, potentially, but that would come with a risk of Stun Spore missing or Rock Slide critting, not to mention Primeape's potential Double Team spam and subsequent Focus Punches: the move can 3HKO Jumpluff despite its resistance. Sleep Powder is also a no-go, as Primeape has Vital Spirit. Poliwrath is easier for Jumpluff, thanks to the Grass weakness as well as lack of moves that are dangerous for it; Focus Punch, ironically its best move, can only 3HKO, much like Primeape. Mega Drain requires several turns to KO, but a combination of Leech Seed and either Stun Spore or Sleep Powder, as well as Awakenings in case Poliwrath manages to hit with Hypnosis, will eventually guarantee Jumpluff victory.
Gym #6 - Jasmine (Olivine City, Steel-type): Jumpluff has good bulk and can take up to three Thunderbolts from the Magnemite. Either Sleep Powder or Stun Spore should work, and Leech Seed will do the rest; as usual, patience is needed to win. Steelix has Iron Tail (stronger than Rock Throw) and should likely be left to a more suitable teammate, unless Jumpluff already has a Substitute up from the previous fights and can Leech Seed the solid snake and keep healing up as the enemy's health is being sapped; Iron Tail is a likely 2HKO against Jumpluff, so victory is unlikely, but with a Substitute already up Jumpluff can start the work that a teammate could later finish.
Petrel (Team Rocket HQ): Zubat's Wing Attack and Koffing's Selfdestruct are bad for Jumpluff, but with its likely level advantage of ten or more, it can respectively 2HKO Zubat and 3HKO Koffing with Headbutt. Koffing, however, can also kill Jumpluff with a critical Selfdestruct, so it should be fought by a teammate anyway, if the risk can be reduced or eliminated. Raticate, instead, is an easy enough opponent to take down, with the usual technique.
Ariana (Team Rocket HQ, tag battle with Lance): Arbok's only STAB is Poison Sting, which will really not do much to Jumpluff at this point; its Intimidate, however, makes Jumpluff's job harder as it nerfs Headbutt, and stalling in double battles is not as effective as it is in single battles, as both Pokémon could theoretically gang up on Jumpluff and break its Substitutes repeatedly. Drowzee has Poison Gas, and this status could easily mess up with Jumpluff's subseed practices, unless Jumpluff manages to put up Substitute preemptively. It is better to take down Arbok first, as Drowzee's moves do little to no damage to Jumpluff, which can as such keep Substitute on more easily. Sadly, the Pokémon that are up next make the fight harder or impossible for Jumpluff to continue: Gloom is immune to seeding and has Acid, and Headbutt can only 4HKO it after Intimidate; Grimer is not immune to Leech Seed but it has Sludge, with high chance of poisoning, and is also a 4HKO by Headbutt. Murkrow has Wing Attack, which is terrible for Jumpluff, and its Pursuit also complicates switching out. If possible, Jumpluff should just be withdrawn before Murkrow comes out, to avoid unnecessary complications.
Gym #7 - Pryce (Mahogany Town, Ice-type): Seel's strongest move is Icy Wind, a 3HKO, and it gets 3HKOed by Mega Drain. Jumpluff can theoretically also take an Aurora Beam from Dewgong if at full health, but its stall will not work well enough against it, as Ice Shard can creep through Substitute and Leech Seed does not sap its health fast enough to function. Lastly, Piloswine has Blizzard. One does not simply have a Jumpluff fight against something with STAB Blizzard.
Petrel (Goldenrod Radio Tower): Everything in this team can explode and has Sludge. Unless Jumpluff wants to Sludge-bait - which might actually work, with Jumpluff's weaknesses - it is much, much better for Jumpluff to never set foot on the battlefield here. Sleep Powder may work, but the 25% miss chance puts Jumpluff in real danger, as even Koffing can kill with a critical Selfdestruct, and Weezing needs no critical hits to do the same.
Rival (Goldenrod Underground): Golbat, Haunter and Sneasel are either untouchable or too strong for Jumpluff to play its stall games safely. Quilava and Feraligatr are both bad for Jumpluff too, the former due to the obvious STAB and the latter due to Ice Fang. The only Pokémon that Jumpluff can realistically fight here are Magnemite and Meganium, and Meganium will need to be stalled out with something other than Leech Seed, so possibly PoisonPowder or, in absence of that, just Stun Spore and Headbutt.
Proton (Goldenrod Radio Tower): He uses Poison-types, and strong ones at that, compared to Jumpluff's relative bulk. Fight him with a more suitable teammate, as this is no job for a Jumpluff.
Ariana (Goldenrod Radio Tower): The team is essentially the same as the Rocket HQ confrontation, notably with Arbok not having gained any better STAB than Poison Sting, thus being annoying at best, but definitely doable. Stall it out with Leech Seed and Substitute. The now-evolved Vileplume and Murkrow, on the other hand, are still a no-go for Jumpluff, which should bow out of the fight entirely at that point.
Archer (Goldenrod Radio Tower): Super effective moves are everywhere to be found. Unless Jumpluff wants to take up a very risky matchup, do not tread here. Not even Sleep Powder would save it, as Houndour and Houndoom both have Early Bird, and could wake up as soon as on the very turn they are put to sleep with a stroke of bad luck.
Gym #8 - Clair (Blackthorn City, Dragon-type): Gyarados is surprisingly good for setting up, as Jumpluff definitely does not like repeated Dragon Rage right in the face, but it can at the very least put it to sleep and then use Substitute to start its seedstall strategy. Healing items will be needed, but there is a good chance of Jumpluff pulling off a solo at almost zero risk. Substitute will also prevent the Dragonair from using Thunder Wave, which is a handy advantage as paralysis cripples Jumpluff, and Kingdra's SmokeScreen will be no bother either. The chances of pulling off a Jumpluff solo are even better if Jumpluff can receive an X Accuracy and/or heal until Gyarados' Dragon Rage PP run out, as the former will guarantee that Sleep Powder and Leech Seed hit and the latter will allow Jumpluff to put up a Substitute again undisturbed, before the scariest of Clair's Pokémon enters the battle. Notably, one of her Dragonair has Fire Blast, which 2HKOs Jumpluff, whereas Kingdra can OHKO anything in sight with a critical hit, due to its Sniper. If Jumpluff never misses Sleep Powder, though, it will not lose: alternating sleep turns and Substitutes, with Leech Seed support, will eventually result in its victory.
Kimono Girls (Ecruteak Dance Theater): Jumpluff is generally a decent lead if it has U-turn, but is otherwise mediocre as a fighter. It can deal a good amount of damage to both Espeon and Umbreon with it - up to a quarter to Umbreon, and half to Espeon - and put them to sleep before switching out if need be. It does lose to Flareon, but the team should have better options to fight it, either way. Jolteon dishes out pain with Thunderbolt, and outspeeds Jumpluff as well; in this case, Jumpluff should have a support role, paralysing it and possibly getting off a Leech Seed before bailing, as Thunderbolt is still a 3HKO without any critical hits. Vaporeon has Aurora Beam, no comment.
Ho-Oh (Bell Tower, HeartGold only): Jumpluff will die if it faces Ho-Oh. Sleep Powder and Substitute may do the phoenix in, but once again, the miss rate is creeping in and a single Fire move is guaranteed to kill Jumpluff, a risk not worth taking.
Lugia (Whirl Islands, SoulSilver only): Much like Ho-Oh, except with Aeroblast instead of its counterpart's Fire STAB. Even here, Sleep Powder is a dicey move to use, and if it fails, Jumpluff may die - Aeroblast does not kill for certain, but comes very close to it, so a critical hit will still off Jumpluff. There are likely better Pokémon to fight Lugia with at this point.
Rival (Victory Road): As not much of his team has changed, neither has the matchup; Sneasel, Haunter and Golbat are as awful to Jumpluff as they always were, and both Typhlosion and Feraligatr are impossible for it as well. Magneton is evolved now, but it has a physical moveset, which does not threaten Jumpluff much; Seed stalling will do the trick. Meganium should also be easy as ever, although annoying to stall out due to Leech Seed immunity. Jumpluff can also take on the new recruit, which is a Kadabra; it can be 2HKOed by a combination of Headbutt and U-turn, or outstalled in the usual ways.
Elite Four Will (Indigo Plateau, Psychic-type): The first Xatu does not have Flying moves, so Jumpluff can take it on. However, it will need a Lum Berry or a healing item to do so, as Xatu has Synchronize. The other Xatu has Early Bird instead, which makes it more difficult to fight with the stallseed technique as it will wake up often; its Aerial Ace is also fairly powerful, netting a 3HKO and thus breaking Jumpluff's Substitute right away. Aside from that, the only other opponent Jumpluff should attempt to fight is Slowbro; Jynx should be avoided for obvious reasons, though Jumpluff can U-turn in front of it if it knows the move, and Exeggutor's immunity to Leech Seed makes it less than likely to be worth the trouble unless, once again, Jumpluff has U-turn.
Elite Four Koga (Indigo Plateau, Poison-type): Everything on his team sans Venomoth is beyond dangerous for Jumpluff, even Forretress, which has no Poison moves but carries Explosion; even Ariados, theoretically the most harmless, can 2HKO with Poison Jab and has Insomnia, which prevents Sleep Powder shenanigans. If Jumpluff does manage to put Forretress to sleep and start the Substitute and Leech Seed strategy, there are chances for it to also defeat Muk as well as Venomoth, but Crobat is an unlikely opponent for anything other than Jumpluff liners with Speed-boosting natures, as it will otherwise outspeed and deal more damage than it is worth. Muk is also hard to defeat due to its Black Sludge, and Gunk Shot can kill even from full health, so Jumpluff should be ready to switch out whenever its Substitute is broken; putting it up again is not worth the risk.
Elite Four Bruno (Indigo Plateau, Fighting-type): Jumpluff's Flying-type is of great help against Hitmontop, which can be stalled easily. The other two Hitmons and Onix all have super effective moves to hit Jumpluff with, and strong ones at that; while Onix easily gets destroyed by Giga Drain, Hitmonlee and Hitmonchan can wreck Jumpluff with Blaze Kick and Ice Punch respectively. Take note, however, that Jumpluff can live a Blaze Kick from Hitmonlee, and potentially a low damage roll Ice Punch as well, though there is no certainty of that happening. Regardless, Jumpluff can only hope to Seed them both and maintain its Substitute up with Sleep Powder, which is not easy due to the accuracy of the move and the ease with which the Hitmons can kill Jumpluff. On the plus side, Machamp offers Jumpluff an opportunity to shine: its No Guard makes Sleep Powder 100% accurate, and as such, the stall technique becomes flawless and a guaranteed ticket to victory. Giga Drain will also speed up the process.
Elite Four Karen (Indigo Plateau, Dark-type): While Umbreon cannot damage Jumpluff much, its Double Team is really annoying and makes landing Sleep Powder a lot harder than it would usually be. Starting off with Leech Seed is the best option, as Jumpluff will at least recover HP while it tries to take down Umbreon. Jumpluff can also fight Gengar, thanks to its not-at-all-bad special bulk and Gengar's main asset being Focus Blast, which Jumpluff resists; Jumpluff will need to pay attention to Destiny bond as it stalls for damage, but do not worry if Gengar faints due to residual Leech Seed damage, as Destiny Bond will not activate in that case. In fact, choosing to simply wait out Leech Seed instead of actively attacking is a good way of circumventing Destiny Bond, which is otherwise dangerous for many slow Pokémon. Vileplume, Murkrow and Houndoom are all to be left to more appropriate fighters.
Champion Lance (Indigo Plateau, Flying-type): Gyarados' Ice Fang is more than enough of a deterrent for Jumpluff to even lead the team, and one of the level 49 Dragonite has Blizzard, but there is no telling which one does as their other moves are the exact same. The ace has Fire Blast, and while this move does not kill from full health, there is little Jumpluff can do against Dragonite unless it gambles Leech Seed hoping that critical hits do not occur, and then gambles further with Sleep Powder to attempt its stall games. Charizard has STAB Air Slash, and Aerodactyl has STAB Rock Slide; both can 2HKO Jumpluff, whose moves do very little damage in return, and Substitute will never suffice to shield it from their hits. All in all, there is no way for Jumpluff to safely partake in this battle.
From this point onwards, you can fight the gyms in any order, though you will need to retrieve the Machine Parts from the Cerulean City gym before you have access to the earlier portion of Kanto. Feel free to anticipate or postpone any battles as needed.
Gym #9 - Brock (Pewter City, Rock-type): Give Jumpluff the Choice Specs and Giga Drain everything. No need to stall here, enjoy the double weakness to Grass while it lasts. Note that the item is necessary to net the OHKO against Omastar, which would otherwise only be 2HKOed; Kabutops is also only OHKOed with a boost, and both of them have Rock moves that can kill Jumpluff with critical hits. The Choice Specs remove that risk.
Rival (Mt. Moon, optional): Same team, same policy. Even though Haunter and Kadabra have now evolved, they are as fight-able as they were before, which means yes for Alakazam and no for Gengar. Jumpluff will still need caution and Sleep Powder for Alakazam, because its Psychic is very powerful (close to a 2HKO), and it can outspeed Jumpluff if their levels are close enough. As for the rest, Magneton's Discharge is only a 3HKO, so it can be put to sleep and then Seeded; Meganium is also the only doable starter, and everything else is off limits.
Gym #10 - Misty (Cerulean City, Water-type): Golduck cannot break Jumpluff's Substitute with less than two hits, which makes it perfect for setups. Jumpluff will easily defeat it with a Substitute still on, and it can then one-shot Quagsire with Giga Drain, replenishing its health in the meantime. Lapras and Starmie will both OHKO Jumpluff with Ice Beam, and Starmie is notably faster than Jumpluff. Jumpluff will need a Substitute already up as well as Sleep Powder to be able to deal with them, and a single miss will foil Jumpluff's plans, so have a switch-in ready.
Gym #11 - Lt. Surge (Vermilion City, Electric-type): Substitute on the first turn to get rid of Raichu's pesky Thunder Wave, then proceed as usual with Leech Seed and Sleep Powder. Jumpluff should be able to solo this fight with some luck, as Lt. Surge's Pokémon have Double Team and the two Electrode can (and probably will) outspeed Jumpluff.
Gym #12 - Erika (Celadon City, Grass-type): Assuming U-turn support, Jumpluff could deal some chip damage before letting an actual fighter take its place on the battlefield, but this is likely not worth the trouble. The immunity to Leech Seed makes it impossible for Jumpluff to be proficient here; use something else.
Gym #13 - Janine (Fuchsia City, Poison-type): The very typing of the gym should already say enough about why making Jumpluff fight Janine would be a really bad idea. Everything 2HKOs it, and Weezing can OHKO with Explosion; Jumpluff would never have the necessary time to set up.
Gym #14 - Sabrina (Saffron City, Psychic-type): Espeon's Speed is tied with Jumpluff's, and it has Calm Mind, which could easily become a dangerous asset against something such as Jumpluff, which kills slowly and painfully. If Sleep Powder misses and Espeon lands a hit, it could be the end of the whole team if there are enough Calm Minds previously set up. This risk is best avoided, though Jumpluff can pull off a victory with some luck in a pinch; alternatively, if it knows U-turn, it can chip away about half of Espeon's health and let a teammate finish the job. Mr. Mime is much easier to set up against, and could be the ultimate weapon against Alakazam, should Jumpluff manage to maintain a Substitute and high enough health levels before Alakazam comes into the battlefield; in that case, the usual stall play will eventually do it in, except in a stroke of bad luck: a critical Psychic from Alakazam is the end for Jumpluff.
Gym #15 - Blaine (Seafoam Islands, Fire-type): Paradoxically, Jumpluff could do well here, if it manages to Substitute its way out of at least three Overheats (all of Blaine's Pokémon have a White Herb attached), but more likely four. Magcargo and Magmar only have that as STAB, while Rapidash also has Flare Blitz, and is therefore more dangerous; still, if Jumpluff manages to set up Substitute and keep it with Sleep Powder, it could actually solo Blaine with enough luck. Do not put anything to sleep without a Substitute on, however, lest Sleep Powder misses at the worst possible moment. And, of course, use something else if available. Jumpluff will make the fight needlessly longer, and if it uses Headbutt to attempt the flinch it will also be exposed to Magcargo's and Magmar's Flame Body.
Gym #16 - Blue (Viridian City): Exeggutor is not prime setup material, being immune to Leech Seed and carrying Trick Room, which will make Jumpluff's job much harder. Assuming U-turn support, Jumpluff can make it here, but it is not worth deleting one of its wonderful stall moves over. Rhydon can be Giga Drained to death, but the OHKO is only guaranteed with the Miracle Seed attached. Machamp can be stalled without worries thanks to its No Guard, which allows Jumpluff to Sleep Powder and Leech Seed it safely, but that is all: Gyarados has Ice Fang, and both Arcanine and Pidgeot have strong enough STAB to make Jumpluff's stall impossible, not counting Gyarados' Dragon Dance, which would eventually guarantee its outspeeding.
Rival (Indigo Plateau, optional): Golbat has also finally evolved, but the difference made for Jumpluff is absolutely none. It can still defeat Magneton and Alakazam with the usual precautions, as well as Meganium, but the rest of his team is impossible for Jumpluff to get the best of without risking its life.
Red (Mt. Silver): Pikachu can be put to sleep with Sleep Powder but, in the unfortunate event that it misses, Jumpluff will have to take a Volt Tackle, and it will hurt a lot; it comes close to OHKOing Jumpluff. Pikachu has a Light Ball and its offensive power is really great. Unfortunately, even if Jumpluff did manage to defeat it with a Substitute on, the others would likely not be worth the trouble: half of Red's team has Blizzard, which has flawless accuracy under Hail, and Jumpluff cannot afford to carry Sunny Day as it needs every single one of its four moveslots to perform its stallseed duties well. Lapras and Blastoise OHKO Jumpluff with their own Blizzard, and Snorlax can do the same, even though in its case the OHKO is not certain; still a moot point, however, as Jumpluff can only hope to ever do anything against it if it already has a Substitute up, manages to hit with Leech Seed on the first turn, and then spams Substitute every single other turn until Snorlax's Blizzard PPs run out. Venusaur has Sludge Bomb too, which is not an OHKO but comes dangerously close, and Charizard has Fire STAB in the form of Blast Burn and Flare Blitz, respectively a certain and a possible one-shot against Jumpluff. All in all, a maybe for Pikachu and not without risks, but the rest of Red's team is out of Jumpluff's league.
Hoppip is one of the hardest Pokémon to train up: it only knows Splash and Synthesis when caught at the earliest point in the game, it learns Tail Whip at level 7, and then gets its first and only offensive move for a while only at level 10, which is the underwhelming Tackle. On the plus side, from that level onward, it learns plenty of support moves: PoisonPowder at level 12, Stun Spore at level 14 and Sleep Powder at level 16. The first STAB move comes only after the evolution into Skiploom; in this form, Bullet Seed is accessible at level 20, though at this point, Skiploom will probably already be on the sleepseed stall path and not need Bullet Seed anymore. On that regard, Leech Seed comes at level 24, which is right where the moveset of this line finalizes in its most used form; together with Substitute from the TM, and Headbutt from the tutor, it is unlikely Skiploom or Jumpluff will need much of anything else until the draining moves become available. Jumpluff learns Mega Drain at level 28, which is quite good paired with Sleep Powder and Leech Seed, at least until Giga Drain. Cotton Spore comes at 32, but is unneeded with Jumpluff's Speed; U-turn comes at 36, and is a rather good move for alternate sets, but will not work well with Substitute. Worry Seed is learned at level 40, but completely useless. Giga Drain finally becomes accessible at level 44, and is basically the last move worth learning by level up; the last two, Bounce and Memento, at levels 48 and 52 respectively, are either inaccurate or just plain suicidal.
Via TM, the most noteworthy move the Hoppip line gets is Substitute, which is crucial to the success of the sleepseed strategy. Energy Ball and Grass Knot are both usually more powerful than Giga Drain, but Giga Drain is generally better as it offers HP recovery, and works really well with Miracle Seed or Big Root. In a sleepseed set, there will not be more room for moves, but it is possible to exploit Jumpluff's fairly good bulk to use an alternate strategy based on Swords Dance, another TM it gets access to in Goldenrod, the same time as when Substitute also becomes accessible. With Swords Dance, Bounce actually becomes a nice move to have, and Aerial Ace is its more accurate equivalent. Sadly, on the physical side, Bullet Seed is all the STAB the line will ever get in these games until after the Champion battle. The last slot can be occupied by Return for maximum power, or U-turn for flexibility, though running Swords Dance and U-turn on the same set is arguably not optimal.
Via tutor, Jumpluff gains access to Seed Bomb which works really well with the Swords Dance set, and Headbutt which will provide a better offensive move than anything the line learns naturally by level until Giga Drain, as well as working well together with Sleep Powder and Stun Spore, and the inevitable Leech Seed.
Water-types: Due to Jumpluff's double Ice weakness and regular Fire and Rock weaknesses, a Water-type supporting it is absolutely necessary. Said Water-type must both be resistant to Ice (thus not part-Flying or part-Ground), and sufficiently bulky to be able to switch in freely when Jumpluff bails out of the battlefield. Fortunately, the Water-type is so common that several Pokémon available in Johto match this description.
Steel-types: While not very common, Steel-types are a near-perfect addition to the team after Jumpluff is supplemented with Water coverage. Steel-types cover for the spots Water leaves open, providing a resistance against Flying-types and an immunity to Poison-types. Although neither of these types is hit super effectively by Steel moves, Steel-type Pokémon usually have Ground coverage or otherwise strong moves, and the resident Water-type can carry Ice Beam to deal with the birdkind.
Strong hitters: Jumpluff is simply bad at dealing damage, because that is not what it was built for. Its fighting style is slow and steady, which can be good to hard-wall Pokémon that glass cannons are unable to defeat; however, against enemies with decent or great bulk which also sport setup moves, Jumpluff is completely powerless. Hard hitters, whether fast or slow, must fill the team in where Jumpluff is lacking.
Minimum stats are calculated with 0 EVs, IVs of 0, and a hindering nature, if applicable.
Maximum stats are calculated with 252 EVs, IVs of 31, and a helpful nature, if applicable.
Hoppip Line Ratings
What Nature do I want? Anything that lowers Attack is good, Bold and Calm being the preferred options, but Modest and Timid are also good natures. Modest will make Giga Drain slightly more powerful, while Timid will help against the faster Pokémon, such as Alakazam. Neutral natures also work well.
Which Ability do I want? Neither is particularly useful, as Jumpluff is unlikely to carry Sunny Day no matter its set. Leaf Guard may be slightly better, though, as Jumpluff really does not need any more Speed than it already has.
At what point in the game should I be evolved? Hoppip should become a Skiploom anytime between before Bugsy to before Whitney, and a Jumpluff by the time Cianwood City is reached.
How good is the Hoppip line in a Nuzlocke? Fairly bad, and even more unfortunate due to its typing and how unkind Johto is to Grass-types in general. However, it is very fun and challenging to use, and can definitely pull its weight against the opponents it was built to fight; they are not very many, however.
Weaknesses: Flying, Poison, Rock, Fire, Ice (x4)
Resistances: Fighting, Water, Grass (x0.25)
Neutralities: Normal, Bug, Ghost, Steel, Electric, Psychic, Dragon, Dark