Help me identify this old game

Ok, this is gonna be s stretch to say the least...

Over the past couple years every now and then I’ll think of this old fighting game... can’t even remember what system it was on. I don’t think it was 64, but maybe, but most likely ps1 or something. See? No idea

All I remember is some of the fighting arenas were dark, with blues and blacks. It wasn’t a 2D fighting arena, you could move all directions. I want to say there was a character with like a zipper head, maybe one with a chainsaw. It was a pretty gruesome game with mature characters... please help lol