Billy eats too much junk food that makes him feel sick. Grim prepares him a remedy using his granny's recipe, but this medicine makes a parasite to start growing in Billy's back, which Billy names Yap-yap. In the following, Billy and Yap-yap continue eating junk food, so Mandy suggest to use the antidote to the original remedy. Eventually, Yap-yap, now looking like a smaller version of Billy, detaches himself from Billy (which would have technically cured Billy without the need of him drinking the anitdote), and tries to escape from the antidote. In the end, Yap-yap drinks the antidote and is destroyed. Major Doctor Ghastly invents the Temporal Confabulationater Izationizer Unit – a time machine that works so well that Ghastly, Hector and Skarr end up meeting their future selves and Destructicus Con Carne, son of Ghastly and Hector, as both an infant and an adult. Billy is constantly provoked by a bully named Sperg and runs over to Grim for help.