It is just a normal Krabby Patty, except it has been dropped into the toilet, etc. While he's eating it, a fly goes into his mouth and' kills' him.
It is just a normal Krabby Patty, except it has been dropped into the toilet and filled with Mr. Krabs's sweaty gym sock, along with other disgusting items. Just before the health inspector eats it, a fly goes into his mouth and' kills' him.