Run around him repeatedly until he gets bored and poops on the floor. Then you throw the poop in his eyes. Once he is blinded, he will spew fire from his rectum in your general direction. Then you must run behind him, climb his shell and fart into his face. He will then be knocked out after repeating twice. Once he is out cold, you throw his body into the Tube of the Underworld.
Really, I have no clue.