第9集 The Problem with Billy比利曼蒂和死神的大冒险 第四季When Billy goes into the mud for the fifth time in the day while wearing his white tuxedo before a wedding, Grim tries to figure out why Billy is so stupid. Billy's dad recounts Billy's life from his birth until he met Mandy and explains that Billy is not dumb, but actually a genius with a certified "Honorary Genius Degree". It is quite evident to Grim that Billy's problem is his equally dumb father.