|Number of Appearances||1|
|Played by||Carl Tart|
|First Episode||Your Cousin Marvin|
Marvin Phelps is a character played by Carl Tart. He is Michael Phelps' cousin. He claims he could have also been an Olympic swimmer, but after the United States boycotted the Olympics in 1980, he became a fry cook. He has been through several bicycle accidents.
|Episode||Release Date||Other Characters||Other Guests|
|441: Your Cousin Marvin||8.22.16||Larry the Loner||Jason Mantzoukas, Neil Campbell|