Pokémon that don't evolve
This is a list of Pokémon that do not have regular evolutions in any of the Pokémon games (ignoring Mega Evolutions). This includes the majority of legendary and mythical Pokémon throughout the games.
Additionally, instead of evolving many of the Pokémon have
counterparts: for example, Volbeat and Illumise are male and female opposites. Zangoose and Seviper apparently have a long history of feuding.