Gengar

A disturbed, angry ghost-type with a distaste for food thieving trespassers. He seeks nothing but to torture those who trespass onto the Old Chateau grounds, and with the ghosts' big dinner ruined, any excuse will do.

This one... Go with a malicious, deep voice, or something similar. As long as it sounds like he's a demented ghost-type more than eager to chisel someone's skull.