Missingno./'M?
I was the first Pokémon whom Ash tried to catch in the Anime.
It was actually Mew. Mew was accidentally found by the Mew glitch. Devs put it in at the last minute.
Spearow
I tried to post an image for a riddle but I couldn't.
Aww, I wanted to solve a riddle. :cer_cry:
Well, I'll make one: I only starred in one episode of the Pokemon anime because a certain mascot made me look bad. Who am I?