|“||Hey! You like bananas? I got her number. How do you like them bananas?||”|
–Guenter, Mars University
Guenter is a monkey made super-intelligent by the Electronium Hat, an invention by Professor Farnsworth. Guenter was originally an experiment to see if a monkey could pass a course at Mars University. Seemingly on top of the world, Guenter was both smart and cute, making Fry extremely jealous. After Guenter's parents, a pair of monkeys possessing normal monkey intelligence, cause a scene at a university party, Guenter decides to revert to his natural state by removing the hat.
When Fry, Leela and the Professor's lives are in danger, Guenter once again dons the hat with some difficulty and manages to save them all, however in doing so he falls down a massive waterfall, damaging the hat. Comfortable with the new "moderate intelligence" the damaged hat produces, he decides to abandon academic greatness in favor of business school, much to the Professor's dismay. He got his MBA and became the president of the Fox Network.
In "Fry and Leela's Big Fling": Amy, Bender, and Zoidberg delivered cars to a planet inhabited by all types of primates. Guenter was one of the workers at the office that Amy, Bender, and Zoidberg were delivering to. He showed everyone around the planet and was with them when they learned that Fry and Leela's "couples only Vacation" was actually in a human zoo habitat. He, Amy, Bender, and Zoidberg went to see Dr. Banjo to try and convince him to let Fry and Leela out. He was last seen being tranquilized after Dr. Banjo learned that Amy was a human.
- Guenter is voiced by Tress MacNeille, without his hat and in primal form he is voiced by Frank Welker.
- According to the commentary from Mars University, Cubert was originally going to take the place of Guenter.