Ozmodiar

Ozmodiar is a little green alien.

History
When Bart and Lisa saw an anime, Lisa was confused by one of the character's abilities. Bart told her that cartoons don't have to make sense, which caused Ozmodiar to appear and agree with him. Later on, Homer's work safety report resulted in the Power Plant getting shut down with all the employees losing their jobs. Ozmodiar appeared and told him he had "Really done it this time, dumb-dumb".

Non-canon
Troy McClure gave a preview of The Simpsons Season 9 which included the introduction of Ozmodiar, who could only be seen by Homer.

Bart and Lisa wrote an unaired television Christmas special starring Ozmodiar, where he appealed to C. Montgomery Scrooge to give his employees time off for Christmas. However, Scrooge was prepared for him, and sent the similar entity Smilin' Joe Fission to fight him off, which caused the world to explode.

Behind the Laughter
Ozmodiar is a parody of The Great Gazoo from the TV series The Flintstones.