The Grim Adventures of Billy and Mandy (2001)

Episode Overview

Billy stumbles into a junkyard, where a colossal pit suddenly opens and swallows him whole. Soon after, Mandy and Grim find themselves drawn into the same abyss. They arrive at the Earth's core, where they encounter Nergal, a sinister being who has been observing Billy and Mandy. Nergal desires Grim to surrender the kids so they can be his eternal companions. Initially, Grim abandons them and returns to the surface, but his guilt compels him to rescue them. Ultimately, Grim is overpowered by Nergal's shocking tentacles, but Mandy triumphs by simply kicking Nergal in the shin.