Full Name: Mario Leonardo Phelps
Also Known As: Tubby, Mister Mario (by Toad)
Birthday: October 9, 1992
Relatives: Luigi Phelps (brother), Milo Phelps (father), Agata Phelps (mother)
Hair Color: Brown (black mustache)
Eye Color: Blue
Skin Color: Fair
Mario always wears a red shirt, navy blue denim overalls with brass buttons, a red hat with a red "M" inside a white circle on it, white gloves, and brown shoes.
- Like Steve Burns and Pinch Raccoon, Mario shares his birthday with 2 late English musicians: John Lennon of The Beatles and John Entwistle of The Who
- He was born Entwistle's 48th birthday
- He taught himself how to play bass and is now the proud owner of a Dean John Entwistle "Hybrid" Model Bass
- His favorite TV shows are the original Hawaii Five-O, Scooby-Doo, and Josie & The Pussycats.
- He and his younger brother Luigi were both raised by an American father and an Italian mother, which makes them Italian-Americans
- He gets his name from his chubby appearance