Nidoran♀ can be found in the following areas: Route 3 (14% in LeafGreen, 1% in FireRed) and the Safari Zone. In FireRed alone, it may be received in a trade for Nidoran♂ on Route 5.
Moon Stones are available in Mt. Moon, the Rocket Hideout, and the Pokémon Mansion. They are also held by wild Clefairy.
Whenever you add it to your team, Nidoran♀ makes for a solid and versatile Pokémon. The evolutionary line sports good, but not spectacular, stats in all areas for each stage. While this means it's not the best thing out there in any particular role, most Pokémon you'll find will still come short of Nidoqueen's base stat total of 495, and, with the family's evenly-spread stats, they perform solidly all around.
Nidoqueen is also available extremely early thanks to a Moon Stone located in Mt. Moon, letting you have a non-Bug third-stage Pokémon by Cerulean! Nidoqueen can absolutely wreck most of the early game with her large base stat advantage. However, avoid over-reliance. Also, while early Nidoqueen is tempting, you may still wish to wait until after Misty and her potent Water Pulses to gain the Ground-type and its corresponding weaknesses.
Being a Poison-type, Nidoran resists Fighting, Grass, Poison, and Bug, which gives it an advantage over Erika's and Koga's Gyms, as well as the Fighting Dojo. It also cannot be poisoned, something you'll really appreciate in the mid-game when Bikers, Cue Balls, and Team Rocket spam Poison-types at you. It does, however, have a weakness to both Psychic and Ground, making it risky to use against certain foes (the enemies in the Saffron Gym being the most dangerous). When you evolve Nidorina into Nidoqueen, it picks up the Ground-typing, which gives it an additional resistance to Rock and doubles its resistance to Poison while granting it an Electric immunity. However, it does lose its Grass resistance while also picking up Water and Ice weaknesses, but it's a fair trade due to the easy availability of Water-types in Kanto for type synergy (they resist the Water and Ice weaknesses for you) and because you'll no doubt have something for Grass, whether it be Bug, Flying, Fire, Grass, Poison, or - if you're lucky - Dragon.
While Nidoran♀ and its family get other abilities in later generations, namely Rivalry and Hustle/Sheer Force, you'll be stuck with Poison Point in Generation III. It's not too shabby, since they can take a hit well enough to actually trigger the abilities, but you'll probably not be trying to stall out anything with these, so it won't be something you'll abuse often, if at all.
Rival (Cerulean City): If you got lucky enough to get Nidoran early, then chances are you'll already have Nidorina, which will match Pidgeotto in terms of stats. Nidorina has no poor match-ups here since Abra only knows Teleport, so as long as you're careful and attentive, it can take on any opponent. It'll have Double Kick by then for the Rattata, though you should watch out for accidentally poisoning it since it does have Guts. It resists Bulbasaur's attacks, but unfortunately said 'Saur resists both Double Kick and Poison Sting, so battling it will likely be a drawn out affair if you've not leveled enough for Bite. If you've gone to Nidoqueen, her stats should be able to easily wreck everything your rival has without trouble (but don't get overconfident). However, Squirtle can hit Nidoqueen super-effectively, so you may wish to give that match-up a pass.
Gym #2 - Misty (Cerulean City, Water-type): Although Nidoqueen is flat-out stronger than Nidorina, the latter is much better suited for this battle due to its lack of a Water weakness. Hence, Nidoqueen should sit out unless you're desperate, but Nidorina should be fine. Staryu doesn't pose much of a problem, but Starmie can be killer with its high stats and STAB Water Pulse. Be sure to pick up Bite at 20/22 for Nidoran♀/Nidorina before coming to this battle, as that'll give you a super-effective attack against Starmie. Otherwise, you may fail to do significant damage without using early TMs, such as Dig.
Rival (S.S. Anne): This match is similar to Cerulean for Nidorina/Nidoqueen with the notable exception that Raticate evolved and also got Hyper Fang, making it a much more dangerous opponent, and you should keep your Nidoqueen well away from Kadabra now since, even though it's physically frail, you don't have anything you can safely hit it with. Pidgeotto offers about the same threat as last time while Ivysaur is probably easier than Bulbasaur due to its lack of Sleep Powder. If you taught it Dig or Water Pulse, Nido can easily take on Charmeleon, especially as Nidoqueen. Nidorina can take on Wartortle, though it should do so with Bite due to Withdraw, but keep Nidoqueen away from that match-up.
Gym #3 - Lt. Surge (Vermilion City, Electric-type): If you haven't evolved Nidorina yet, now is the time to do so unless you really, really, really want Crunch. Nidorina can take on anything here with its neutral match-ups, but it's a little risky to do because of all the Paralysis and Raichu being a Double Team spamming jerk. Nidoqueen, however, makes Diglett look like a poor option in comparison, especially if you taught it Dig. The most threatening Pokémon to Nidoqueen is Voltorb and its Sonicboom, so keep your HP above 20 with it. After that, all you have left are Quick Attack/Double Team spamming Pikachu and Raichu, who Nidoqueen can make short work of with Dig; in case you can't and they get too haxy, never fear, Poison Point is here! Quick Attack spam will ensure they poison themselves sooner or later, so if all else fails, grab your Nidoqueen a few Potions, a long book to read, and just have her chill while the Double Team spammers slowly succumb to poison.
Rival (Pokémon Tower): Either Nido works fantastically in this battle and, with access to Celadon by this point, you'll be able to have pretty much whatever coverage your heart desires, especially if you take the time to grind out Coins from the Game Corner. Pidgeotto continues to become less and less of a threat, especially now since you can blast it with Thunderbolt, Thunder, Shock Wave, Ice Beam, Blizzard, or Rock Slide. Nidorina should avoid the hell out of Kadabra, but if you're absolutely forced to, you can attempt to KO it with Bite or, better yet, Shadow Ball. Nidoqueen might be able to take a hit, but it also might not, so only try this if you have no other choice. Beyond that, Growlithe and Charmeleon can be taken down with Dig, Rock Slide, or Water Pulse, though the former's Intimidate can be annoying. Exeggcute has no Psychic moves yet, barring Hypnosis, so it can be downed with Aerial Ace, Ice Beam, Blizzard, Bite, Flamethrower, or Shadow Ball. Ivysaur's movepool continues to suck more and more against the Nidos, as it now has Poison Powder to spam uselessly, and can be done in relatively easily. Gyarados does not have any Water attacks this round, so, with it likely being one of your few fully-evolved Pokémon, Nidoqueen is perfectly suited to take it down, especially if you have an Electric attack. Nidorina can take on Wartortle with an Electric attack; Nidoqueen can as well, but this is risky for the same reasons as Kadabra. The 'tortle will compensate for its lack of firepower with durability.
Giovanni (Rocket Hideout, Ground-type): Neither Onix nor Rhyhorn have Ground-type moves, which means your Nido can take either on with appropriate coverage - preferably Special coverage, since both have much higher Defense than Sp. Def. Kangaskhan's Mega Punch can be quite dangerous, but Nidoqueen has the stats to stand up to it and, if you still have Double Kick, can hit it super-effectively. Be careful, though, as it is still a dangerous opponent.
Gym #4 - Erika (Celadon City, Grass-type): Nidorina has a significant advantage here over Nidoqueen in that it resists everything Erika can throw at it except Constrict. However, Nidoqueen is not hit super-effectively, and its higher stats and access to Celadon TMs means it can step into this battle just as well. Just simply keep an eye on their health and spam your choice of Aerial Ace, Ice Beam/Blizzard, or Flamethrower; if you don't have those, Dig hits everyone but Tangela neutrally and you can always use other neutral attacks, such as Shadow Ball, Bite, or Body Slam, to smack them around.
Gym #5 - Koga (Fuchsia City, Poison-type): Nidoqueen makes up for Nidorina's advantage with Erika by having 4x resistance to Poison to stack on top of its handy Toxic immunity, meaning that Koga can do little but chip damage and accuracy/evasion hax - the latter of which can be negated with either Aerial Ace or Shock Wave (if you still have them). Koffing's Selfdestructs can be nasty, but a properly levelled and healthy Nidoqueen should be able to withstand them without much difficulty. Outside of that, Koga will offer almost no resistance. Three of his Pokémon are immune to Dig, so you'll have to hit them with coverage attacks, but considering that Nidoqueen can only take scratch damage in this battle outside of a couple of booms, such a concern is trivial (Dig still has utility if you want to play prediction against the suicide bombers).
Fighting Dojo (Saffron City): Nidoqueen's resistances to Fighting make it a great choice for this pseudo-gym. It can take pretty much anything anyone here can dish out and shrug it off. Hitmonchan does carry Ice Punch, but coming off base 35 Special Attack, it might as well be hitting you with Tackle.
Rival (Silph Co.): Match-ups actually change a little bit. Pidgeot is fully evolved now, but still only has Wing Attack to hit you with. Feather Dance can be annoying, but your Boltbeam coverage won't care (assuming you have it, of course). Alakazam can actually be safely taken on since it only has Future Sight as an attacking move, which does not apply type effectiveness, meaning Alakazam can only hit Nidoqueen neutrally, and slowly at that (It'll probably still hurt, though). Simply bash it with a physical attack and move on. For the Grass-types, Exeggcute now has Confusion and Reflect, which can make it threatening, but Nidoqueen can take it on with the correct coverage in a pinch (Use someone else if you have an alternative, however). Venusaur is packing Razor Leaf now, making it a bigger threat unless you're still using Nidorina, but it's still beatable. As for the Fire-types, Growlithe does little more than annoy with Intimidate. Charizard, however, lost its Dig weakness and is packing Flamethrower, so it can be quite dangerous if you're lacking an Electric or Water (or, better yet, Rock) attack. Finally, regarding the Water-users, Gyarados is easier than ever since it lost Thrash and still hasn't learned a Water move, and thus it can be downed easily. As always, keep Nidoqueen away from Blastoise. While its choice of Bubble + Water Gun still sucks, it's tanky as heck now and you risk being worn down while trying to wear it down (although it's still doable if you absolutely must).
Giovanni (Silph Co., Ground-type): You can demolish Nidorino, Rhyhorn, and Nidoqueen all with appropriate coverage, especially with your own Nidoqueen, since they lack the moves to adequately harm it. Kangaskhan still poses about the same threat level as it did back in the Rocket HQ; while you can take it on, be careful.
Gym #6 - Sabrina (Saffron City, Psychic-type): NO. While Nidoqueen can Shadow Ball the heck out of most of this gym and Flamethrower Venomoth, everything is packing Psybeam or stronger. This is the first gym battle where using Nidorina or Nidoqueen is a sure way to get it killed, but on the bright side, if you're forced to use it, at least you have super-effective options.
Gym #7 - Blaine (Cinnabar Island, Fire-type): You Surfed to get here, right? If so, then there's a chance that your Nidoqueen might actually be the one to know Surf! In any case, with either Surf, Dig, or Rock Slide, Nidoqueen is suited to take this gym on. While it can't do it as safely as a Water-type, since it lacks a Fire resistance, it can still take a Fire Blast to the face and hit back. If you're lacking a Water-type for whatever reason, it might not be a bad idea to teach Nidoqueen Rain Dance for this battle to give it a pseudo-Fire resistance. Everything here is fast, fairly powerful, and packs Fire Blast. Growlithe and Arcanine both pack Intimidate, which can be annoying if you're using physical moves against Blaine, and Arcanine is also fairly bulky, so while Nidoqueen can wreck this gym, you should still be careful.
Gym #8 - Giovanni (Viridian City, Ground-type): Here's the problem: everything Giovanni is packing has Earthquake. Your only Ground STAB against them is Dig. Hence, Nidoqueen is actually a poor choice here, despite theoretically having at least a 50/50 shot against its mirror and pseudo-mirror match against Giovanni's Nidoqueen and Nidoking. However, if you have an Ice or Water move, you can blast everything super-effectively, so if you can take a hit, outspeed, and 2HKO, you can take it on (barring occasional A.I. stupidity that'd let you do it safely). However, you're still best off not using Nidoqueen at all in this battle if you can help it.
Rival (Route 22, pre-Elite Four): Most everything from the previous battle applies here, except: Alakazam now packs Psychic, so Nidoqueen should avoid the hell out of fighting it once more. Gyarados now packs Hydro Pump, so taking it on is a risky proposition, even with an Electric attack, but it can be risked if absolutely necessary. Exeggcute no longer has a Psychic move, so Nidoqueen can bash it around once more. It does now have SolarBeam, but that's not a problem if you have Protect. Rhyhorn is a new addition and packs Horn Drill, but the OHKO can be avoided by leveling to 46 or above, in which case the rock rhino is harmless. The starters are pretty much the same situation, though Venusaur has swapped its Leech Seed stall shenanigans for Synthesis stall shenanigans, which is less dangerous but potentially more annoying. It also has Growth now, so try to down it before it gets going!
Elite Four Lorelei (Indigo Plateau, Ice-type): As the E4 member who packs a bunch of Water, Ice, and Psychic attacks, this is the last battle where having Nidorina would still be somewhat advantageous (although you'll probably have long since evolved unless your rules prevented you). While Nidoqueen can hit everything here with a combination of Thunder(bolt) and Shadow Ball, everything can hit back super-effectively with STABs. About the only thing Nidoqueen can take on is Cloyster, and only if you have Protect to block Dive.
Elite Four Bruno (Indigo Plateau, Fighting-type): Both Onix know Earthquake, so unless you can OHKO (most likely if you have Surf), let someone else take them on just in case. Nidoqueen can thrash them, sure, but why take the risk? Hitmonchan packs Counter, which can be dangerous, but also avoidable by using special attacks, since it can only tickle Nidoqueen otherwise. Hitmonlee's Facade and and Mega Kick make it more threatening, especially if you poison it by accident, making it the most dangerous 'mon on his team for Nidoqueen. Machamp is strong, but has no way to hit Nidoqueen even neutrally. It has Bulk Up though, so hit it on the special side and watch out for an accidental poisoning, since it is packing Guts. Too many Bulk Ups + Guts will undoubtedly end you, but so long as you're properly levelled, it shouldn't get to that point.
Elite Four Agatha (Indigo Plateau, Poison-type): Her team suffers terribly from not having the physical/special split. All of her Ghosts' attacks are either physical or indirect, rather than using their impressive special attack. If you have Shadow Ball, Nidoqueen can make short work of all three of them (they're immune to Earthquake/Dig), though watch for their indirect damage tricks. Haunter knows Dream Eater, so if it puts Nidoqueen to sleep, be sure to wake her up ASAP with the Poké Flute. The same applies to her ace Gengar, as it knows Nightmare. Golbat's inferior stats mean it can't hurt you much and goes down easily. The worst Arbok can do is Screech + Iron Tail, which can still hurt, but Earthquake/Dig should do it in before then.
Elite Four Lance (Indigo Plateau, Dragon-type): His whole team is weak to Boltbeam coverage, so Nidoqueen could easily solo him with some team/item support in case he lands some Outrages or Hyper Beams (both of which hurt, needless to say). His lead, Gyarados, lacks a Water-type attack, so an Electric attack will make quick and safe work of it. From there, his Dragonairs lack the stats of a fully-evolved Pokémon, so Nidoqueen should be able to Ice Beam them down safely. The second one carries Thunder Wave, which makes her a good choice even if you lack Ice Beam since she can't be paralyzed. Aerodactyl, while potentially scary, lacks the correct moves to inflict much harm outside of Hyper Beam. Dragonite has impressive stats, as always, and can inflict a great deal of harm if you let it, but an Ice Beam or two should do it in without trouble.
Champion Rival (Indigo Plateau): The same match-up rules continue to apply, for the most part. In terms of notable changes, Rhydon now packs Earthquake, making taking it on a bit unsafe due to mutual super-effective STABs on each other (though if you're still packing Surf, you can likely outspeed and destroy it before it moves). Exeggutor and Arcanine both finally evolved. The former still packs no Psychic attacks, so Nidoqueen can fight them both if you need her to, though they'll hit back neutrally with Giga Drain and Flamethrower. Finally, in the starters department, Charizard upgraded to Fire Blast, making it very dangerous, but still beatable with your usual anti-Charizard options. Blastoise finally went from Water Gun to Hydro Pump, making fighting it a certain no-go unless you have absolutely no choice. Finally, Venusaur can be incredibly scary if not approached right. However, with a combination of Rain Dance + Protect (to cancel its Sunny Day and block Solar Beam, respectively), it can be beaten without taking a single point of damage because SolarBeam is its only damaging move! You may want an X Speed to ensure you outpace it, though (However, fighting Venusaur means you should have Blastoise, who learns both Rain Dance and Protect naturally and suffers far less from 4-move-slot-syndrome, so unless you lost your tortoise, Nidoqueen doesn't need to be the one doing this).
Post-Game: Despite Nidoqueen's amazingness, having her fight Mewtwo is still a bad idea; a worse idea than having her fight Sabrina. On the upside, the League rematches are actually still pretty good.
Nidoran starts with Scratch, Growl, and possibly Tail Whip if you catch it on Route 3. It's level-up movepool is a little lackluster, though useful in the early game with Double Kick at 12 for all the early Normal and Rock types. Poison Sting, while weak, is its only natural STAB at 17/18. Bite comes in at 20/22 and is the last notable move until Crunch at 47/53. Nidoqueen is notable, as it actually has a couple of level-up moves despite being a stone evolution. It learns Body Slam at 22, which is a very solid move all around despite not hitting anything super-effectively, and then at 43, it learns Superpower, which is a powerful, but somewhat dangerous Fighting move since it lowers your Attack and Defense.
Its TM movepool is where the line really shines, as it can learn pretty much every good TM and HM in the game, including many buyable ones, meaning Nidorina and Nidoqueen are very versatile and can cover just about any gap in your offensive coverage. Notable moves pre-Celadon include Water Pulse, Shock Wave, Aerial Ace, and Dig. Once you get past Rock Tunnel and beyond, Nidorina can get Ice Beam, Blizzard, Thunderbolt, Thunder, Return, Rest, Protect, Thief, and Iron Tail. Evolving to Nidoqueen adds Earthquake, Shadow Ball, Brick Break, Flamethrower, Fire Blast, Surf, and Strength to her repertoire. Both forms also learn moves such as Toxic, Rain Dance, Sunny Day, and Taunt for more situational uses, and post game, there's Sludge Bomb for both of them.
Oh, and it gets better. Move tutors? Nidorina can pick up Body Slam (learned by Nidoqueen), Double-Edge, Substitute, and the risky Swagger and Counter. Nidoqueen gets even more by adding Mega Kick, Mega Punch, Rock Slide, and Seismic Toss as even more options.
Let's be honest here: you're going to have more moves you want than you'll be able to learn, but that's a good thing because, if there's an opponent you want to hit super-effectively, Nidoqueen can learn a move for it, and with its good Attack and Special Attack, it can actually make effective use of all of its options.
Recommended moveset: With a wide movepool and the stats to use them, Nidoqueen's options are too varied to narrow down. Thunderbolt, Ice Beam, Shadow Ball, Earthquake provides great coverage.
Other suggestions include switching Rock Slide over Shadow Ball for Edgequake coverage, which could be particularly useful if you chose Bulbasaur and need something to handle that Charizard.
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.
Nidoran♀ Line Ratings
What Nature do I want? With Nidoqueen being so versatile, almost any nature works. However, with how even its stats are, you'll want to pay more attention to how they're growing on level-up than to what the nature indicates; with lopsided offensive IVs, an Adamant Nidoqueen might end up having better Sp. Atk than actual Attack!
At what point in the game should I be evolved? Nidoqueen can be obtained virtually as soon as you evolve Nidoran to Nidorina, and it'll dominate the early game with its huge stat advantage. However, you may wish to wait until you have Bite and/or until after you have defeated Misty. You also may want to evolve no later than 22 so you can pick up Body Slam for the early game, as, with Shadow Ball being a renewable TM, there's really no reason to wait for Crunch. This might pressure you a little if you plan on using Nidorina against Misty's Starmie, in which case you may wish to delay Nidoran's evolution to 20 for Bite, evolve at 21, beat Misty, and then evolve again at 21 or 22. Delaying Nidorina's evolution until post Erika can also be advantageous, but not so much that it's something you should really do unless you're really hurting for options against Grass-types. Theoretically, waiting until post-Lorelei would also help for the E4, but Nidorina's stat total will be bordering on unusable in the late game, so this is not advisable. If you picked Charmander and don't have a good answer to the rival's Squirtle, you may also wish to delay evolution for a while so you can use Nidorina against Squirtle/Wartortle. If you get a Safari Zone Nidoran/Nidorina, just evolve to Nidoqueen right away and fix its movepool with Celadon's lovely renewable TMs.
How good is the Nidoran♀ line in a Nuzlocke? With its versatility and good power, this line is amazing to have around. While the early movepool might be a little lacking, the ability to have a fully evolved Pokémon with a base stat total of 495 after the first badge is absolutely ridiculous. Butterfree and Beedrill do not hold a candle to Nidoqueen's early game prowess, and, unlike them, all of the renewable TMs in Celadon will ensure Nidoqueen remains a powerhouse in the mid-game by giving it access to amazing coverage and high-powered moves when most trainers are still struggling to use attacks stronger than 60 base power. In the later stages of the game, Nidoqueen hits a couple of snags in important match-ups, since its stats are no longer well above the competition and three of the bosses focus on types that Nidoqueen matches up poorly against. However, very few opponents that you'll face carry a coverage move that hits Nidoqueen super-effectively, which means it can take on just about everything else in the game. Additionally, even when it's at a type disadvatange, Nidoqueen still has the potential coverage to be able to fight back in a bad situation, unlike, say, Jolteon who would struggle greatly against Ground-types without lucking into Hidden Power Ice, Water, or Grass. If you get a Nidoran, care for it, nurture it, and you'll have a Pokémon that'll be more than capable of helping you win your run.