Yakuza

Yakuza (yep, that's his actual name) is a a giant mutant jumping spider who is the archenemy of Serris

He is Just as bloodthirsty as his archenemy, allthough he is much more intelligent but he can still be tricked by people

Yakuza seems to take delight in killing people and causing them pain unlike his archnemesis who only kills because he can, therefore he cam be considered more evil than serris