The Cavity Demon is the main antagonist of the episode, Meatball Party.
It lived in Raven's tooth and ate all the Titans after being free when one of Raven's teeth cracked. It would attack anytime Raven opened her mouth. Inside Raven's mouth, the Titans fight the Demon but are having much trouble, until Cyborg seals the tooth back up with meatballs, presumably banishing it back into her tooth.
- Meatball Party (debut)
- It has been described as a demon octopus.