Big Trouble in Billy's Basement

"Big Trouble in Billy's Basement" is an episode from the first season of the animated television series The Grim Adventures of Billy & Mandy.
==Synopsis==
Shortly before giving Mandy a pedicure, Grim warned Billy not to read The Bad Book. Despite this, Billy decided to read it anyway, leading to him getting possessed by the extra-dimensional entity Yog-Sothoth, who wanted to open a portal from the mortal realm to his dimension and destroy the world. Now under Yog-Sothoth's power and influence, Billy beat up Grim and stole his Scythe, using it to open up the portal in his basement, transforming his house into an eldritch location in the process. Teaming up with Hoss Delgado, Grim and Mandy find out that the only way to close the portal is to throw The Bad Book into it. After Billy swallowed the book, Mandy pushed him into the portal, ending the threat of Yog-Sothoth. However, the Outer Gods didn't feel like dealing with Billy for an eternity and decided to send him back to the mortal realm.
==Behind the Mythos==
*Although it's never explicitly stated, The Bad Book is most likely meant to be the Necronomicon.
*A much later episode "Prank Call of Cthulu" features a similar premise with Cthulhu being the antagonist. 
Category:Expanded Mythos Film & Television
Category:Crossovers