After Grim's robe comes out of the washing machine, Billy and Mandy find Thromnambular, a talking skull with ruby eyes and a number nine imprinted on his forehead. Then, Grim tells them that the skull is a magical artifact imprisoned on Earth that must grant his nine wishes in order to be free. When Mandy asks Grim why he hasn't used any of the wishes, Grim tells her that the skull will corrupt the wishes and end up affecting the wisher. Despite this, Billy runs away with the skull and makes the first wish: (1) he wishes to be in an adventure (which parodies Indiana Jones and Jonny Quest), this backfires because Irwin is eaten, which Billy complains about getting him in trouble. After this, Thromnambular is found by different people who each make a wish: (2) Billy's dad wishes he could live again his High School years, but this backfires because he is not popular; (3) General Skarr wishes to rule on high, but this backfires because he asphyxiates in space; (4) Irwin (despite being eate