Fosse McDonald
| Gender | Male |
| Age | 9 |
| Hair Color | Black |
| Occupation | Student |
| Grade | 4th Grade |
| Voiced by | Trey Parker |
| First Appearance | Big Gay Al's Big Gay Boat Ride |
Fosse and his friend Bill Allen are always hanging out with each other, laughing and calling things gay. They're mostly background characters, but have made a few appearances, like in "Big Gay Al's Big Gay Boatride" and "Lil' Crime Stoppers".