Relationship with Krusty
Like Krusty, he is a heavy smoker, and often seems depressed off-stage. He was once seen playing Wii Sports with Krusty. He is sometimes seen as Krusty’s driver, accountant, and butler. He's a classic act in Krusty´s show when he does "monkey business". Mr. Teeny also rescues Krusty from a bomb carried by a brainwashed Bart. Krusty refers to Mr Teeny as a monkey, although his lack of a tail indicates he is a chimpanzee.This is because Krusty has poor knowledge of animals, even referring to Lemurs as monkeys.
Mr. Teeny is originally from Brazil. His uncle was once the head primate at the Bureau of Tourism in Brazil and his mother's name is Toot-Toot, and she calls him Louis when they're reunited.
Also, it's revealed there have been other apes that went by the name "Mr. Teeny," and that the current one and the very first Mr. Teeny couldn't hold a candle to the third Mr. Teeny (Krusty admitted the second Mr. Teeny was okay since he helped Krusty pick up women).  Krusty once called the current Mr. Teeny in his possession Mr. Teeny Number Seven.
Teeny was a writer for the “Good Guy Awards” and quit after being insulted on-stage by Krusty.
He is an immigrant from Brazil and was deported when Krusty went broke, but has since returned. In "Coming to Homerica" while playing chess with Mr. Teeny, Krusty said that "you fell for my trap just like in Africa" hinting he was born in (or at least lived in) Africa. Since there has been more than one Mr. Teeny some of them may have come from Africa while others came from South America. As he appears to be a simian, lacking a tail, his distant ancestors would have been African, even is his parents aren't, meaning his parents must be an invasive species, as non-human simians aren't indigenous to South America.
He wears a pink hat and bow tie, but has also been seen in a tuxedo and gold encrusted thong.
Krusty has implied that if he can't find a human willing to donate a lung when he gets cancer, he's planning on harvesting one from Mr. Teeny.
Behind the Laughter
He is voiced by Dan Castellaneta. Captions are sometimes added when he speaks.
- In the third part of the anthology comic “Dr. Nick Night,” it is made apparent that Mr. Teeny is a girl, though many facts contradict this. It is possible that since there has been more than one Mr. Teeny, one of them could have been female. This theory can be further supported by the fact that the Mr. Teeny in the comic has a different appearance.
- Despite being referred to as a monkey, neither Mr. Teeny or his mother have a tail, so technically they're apes.
- In the episode "Fraudcast News", "Wedding For Disaster", and "Elementary School Musical" it's revealed there have been many Mr. Teenys.
- Mr. Teeny has a plaque on the Springfield Wall of Fame.
- Even though Mr. Teeny is called a monkey, the fact his arms are longer than his legs and that he doesn't have a tail suggests he is in fact a Chimpanzee, not a monkey.