MudBud is the filthiest of all the Buddies, hence his name. He wears a blue handkerchief for a collar and usually ends his sentences with "Dude." He likes rolling in dirt patches and hates getting soapy baths. In Snow Buddies, the white snow he was trudging through washed away all the mud on his fur, much to his dismay. Luckily, when the Buddies arrived back in Fernfield, MudBud rolled in a patch of dirt to make his fur look like the way it used to be. He lives in Fernfield, Washington, with his famous all-star father Air Bud (Buddy) and his mother Molly. His owner is Pete, a boy who was at first addicted to handheld video games, until MudBud taught him how to loosen up and be more outgoing.
- To date, Snow Buddies is the only Air Buddies installment in which MudBud temporarily loses his dirtiness.
- He is very similar to Ample Grime from Darkwing Duck in that they are both obsessed with filth, but unlike Ample Grime who is a villain, MudBud is a hero.
- In Santa Buddies, he is shown wearing a red handkerchief.
- According to Buddha in Treasure Buddies, MudBud appears to have the spirit of his great grandfather, Digger, inside him in that they both love dirt.