Demon

The Demon is a minor supporting character in Teen Titans Go! who first appears in the episode Driver's Ed. At its introduction, it is depicted as being "evil" as Raven was in the process of banishing it to another dimension before being interrupted by Robin, but somewhere along the line they seemed to have become friends and Raven's pet/little buddy.

Bio
The Demon is a black, winged creature with white eyes and pupils, resembling a ram. It is seen being shot with a blast of psychic energy by Raven. Supposedly, Raven was trying to make it go back to the demon world but was interrupted by Robin. It recovered from from Raven's blast and slithered out of the portal. Later in the episode it is seen eating a seagull and then plays a major role in dragging Ed back with it to the demon world. In "Staff Meeting," Raven finds Robin's staff to be useful for her because she easily whacked the Demon back into its portal with it.

Raven has apparently made friends with it and it has now become her "little buddy", as it fought against Pain Bot for her in the "Little Buddy Showdown" in "Little Buddies."

Season 1

 * Driver's Ed (debut)
 * Staff Meeting (cameo)
 * Little Buddies

Season 2

 * Knowledge (cameo)

Trivia

 * It is still being debated if it is an ally or an enemy of the Teen Titans. This is because Raven tries to banish it two times, but it helps the Titans get rid of Ed, but it also eats a number of harmless animals and causes havoc around Jump City. It possible it's either an anti-hero or an anti-Villain (a person who lacks hero/villain duties).