What is the most evil Pokemon?

Answer 1

well theres really no evil Pokemon but there is a dark Pokemon hondome is the dark Pokemon so its evil i guess and mew two hes evil to!

actually mewtwo isn't evil he is just really angry. the only truly evil Pokemon is spiritomb, the ghost dark type Pokemon from generation 4.it loves nothing more then to reak havok and cause cause so it was sealed away in the odd keystone to trap it inside.-pokitrokit

That or Darkrai, who is a dark ledgendary Pokemon. Apparently he's done many evil deeds and rather than his evilness being apart of his nature as a Pokemon like Spirit Bomb, it is his intent ehich is truly evil as he is very cunning.

Answer 2

When you take into consideration the evil acts of each Pokemon in the Anime and the motives driving the acts; Mewtwo comes off as the most evil. He murdered humans and wanted to destroy the world for his own personal gain (which was ultimately his misunderstanding anyway).

You could also interpret "dark" or "ghost" type Pokemon as evil.

For a list of dark or ghost types, check bulbapedia.