From Bulbapedia, the community-driven Pokémon encyclopedia.
I will have a huge project listing all the appearances of anime characters in main series episodes, side story episodes, movies, Pikachu shorts, The Electric Tale of Pikachu manga, and Ash & Pikachu manga. Because there would be otherwise too much things in one page, there are subpages for each characters and categories.
Main cast and walking Pokémon belonging to the main characters
Team Rocket trio
Relatives of the main cast
The characters of the day pages include not only humans, but also Pokémon with a CoTD status (such as Pink Butterfree, Meowzie and the Crystal Onix).
Game animation characters
This page includes characters appearing in the miniseries Pokémon Origins and Pokémon Generations, as well as the animated trailers of Black 2 and White 2 and Omega Ruby and Alpha Sapphire.