Etermalden

A traditional fake Pokemon (fakemon) that is believed to live in an ancient cemetery. It likely originated among death metal and black metal fans who may or may not have been real-life Satanists, as legends about this Pokemon deal with dark and fucked up themes like cannibalism, church burning, misanthropism, and religious violence.

Definitely one of the darkest and most horrifying Pokemon creepypastas, don't look it up unless you're ready to potentially see straight-up gore and extreme portrayals of evil.