Mythical Pokémon (23)

Mythical Pokémon are the rarest of all: most can't be obtained through normal play, only through special distributions, events or links with other games. There are 23 of them: 1 in Generation 1, 1 in Generation 2, 2 in Generation 3, 5 in Generation 4, 4 in Generation 5, 3 in Generation 6, 5 in Generation 7, 1 in Generation 8, 1 in Generation 9.

Not to be confused with Legendary Pokémon, which you meet over the course of the adventure.