With only 100 Pokemon added in Generation II, there unfortunately wasn’t much room for new Poison-type Pokemon.
The trade off is that many Generation I Poison-types are available in Pokemon Gold and Silver. Tentacool, Nidoran, Koffing and other similar Pokemon are scattered all over the Johto Region. Even Koga, the Poison-type user of the Elite Four, only uses two Generation II Pokemon (Foretress and Ariados). Therefore, the battle for most popular Poison-type Pokemon from Johto becomes a fairly simple contest. Here are the three most popular:
Note: This article is subjective and reflects the opinion of the writer.
3 most popular Pokemon from Johto
#3 - Qwilfish
Sadly, this Pokemon is easily forgettable. Qwilfish is absent through most of the Johto Region. There is one fisherman on Route 42 by Mt. Mortar who uses a Qwilfish in battle, and it’s the first time most players see this Pokemon in their entire playthrough (also could be the last time they see one). The only way to catch this is to bring a Super Rod to Route 32 (or a couple Routes in Kanto) and try to fish for it. Players can only get a Super Rod, however, by going into Kanto and finding a house south of Lavender Town. So, they could only use Qwilfish for the final quarter of the game anyways. By that time, they could have Ho-oh and Dragonite on their team, so they would be hard pressed to use Qwilfish.
#2 - Ariados
The only reason this is more popular than Qwilfish is because it’s featured in Koga’s Elite Four battle. Players can go collect the eight gym badges in Johto and not even know of Ariados’ existence. It’s exclusive to Pokemon Gold, and even then the only way to catch it is at night at Route 30. This is a shame, though, since Ariados is actually a pretty cool Pokemon with an interesting design. Game Freak even gave this Pokemon a signature move in Sticky Web. Unfotunately, though, it doesn't have the best stats or movepool either. Ariados can just fall behind really quickly in any Pokemon Gold run.
#1 - Crobat
Image via The Pokemon CompanyUnfortunately
If not for anything else, Crobat is the most popular Poison-type Pokemon simply because it was an extra evolution to Zubat, one of the most common Pokemon in the game. In Johto, Zubat can be found as early as the Dark Cave, east of Violet City. With Crobat, players could get access to a very powerful Pokemon early on. This new evolution was a large step up from Golbat, with considerably more speed and power behind it. It also evolves by maxing out Crobat’s happiness. It can be a pleasant surprise when Golbat levels up at some random point and begins to evolve. Crobat is a perfect example of taking a slightly lack-luster Pokemon and improving on it to make it way more valuable.