Green is the head of the slicing conveyor belt in Hell (THOH IV).
History
He first appears in Treehouse of Horror IV while Homer Simpson receives punishment from Flanders the Devil. Homer is sent here after finishing a donut which Homer sold his soul to the Devil (Flanders). Marge Simpson insists on a trial, which the Devil agrees too. However, Homer is to spend a night in Hell. It is here where Homer undergoes numerous tortures, one being the Green Demon's torture. He slices Homer into many pieces, and uses them as hot dog meat.