My favorite Pokémon is Skuntank, so of course it's my favorite poison type Pokémon. I saw this fan artwork of this skunk Pokémon online and then it quickly became my favorite Pokémon. I used it a lot in various Pokémon games since. Its most interesting move is Flamethrower, it's impressive to learn a fire type move like that. I like how it's a skunk Pokémon with a tail that can shoot out poisonous projectiles, flames, and skunk spray like a real tank.
Its face looks kinda like a cat, which may be related to the fact that skunks are sometimes called polecats. But its facial cheeks are tan and looks like a pair of buttocks, it somehow also has a butt chin, and also when you look at it from below, it still looks like a butt. Pretty cool.
Gotta say the bug horse, Scolipede. I liked the design already, but I also used him competitively and he was a surprising hero. He was just meant to be a fast lead setting up toxic spikes, but you get 4 moves so he also got megahorn, agility, and baton pass. Dont underestimate STAB megahorns folks, this guy swept through a lot of teams on his own.
Mine is Trubbish, I know a lot of people hate him because he's a prime example of the unpopular "Everyday object come to life, and that's the pokemon", but I just have a softspot for what's known as "Ugly Cute"
Where you take something that should be repulsive (In this case a trash bag), and make it adorable!
Toxicroak, the idea of a poisonous fighting frog is just so cool, the shiny in particular really gives off that "brightly colored animals are poisonous" vibe.
I really like ghost types, so the fact that my favorite ghost is also poison made this an easy choice. I love the Ghastly line's design and the personality they usually have it display. I think they're really cool despite their silliness, and they (used to) have some of the best shiny forms IMO. Gengar has always been a staple on my playthrough teams whenever i have access to it, and sometimes even competitive oriented teams when it works.
Hisuian Sneasel and Sneasler! Weavile is my favorite Pokemon and I was so happy to see its line get some love. Also, Ingo is my new favorite Pokemon character thanks to Pokemon Legends Arceus and the resurgence in the Subway Bros' popularity means there is so much fan art of the Hisuian Sneasel line and that makes me really happy
Ever since I got spoiled on grafaiai, it instantly became my favorite poison type. The gen 9 mons can be hit or miss for me, but I just absolutely adore grafaiai for the design, despite not liking the shiny.
Nidorina.
Design-wise it just encapsulates the idea of a pocket monster for me. It’s not amazing competitively, but I used it all the way back in RBY and Stadium, and it’s stuck around on my teams ever since. I’m not keen on the design of Nidoqueen, so I never bothered to evolve it.