Forrest Griffin Ultimate Underbite

Underbitten UFC Fighter Forrest Griffin was a finalist in the first season of The Ultimate Fighter (his opponent was Stephan Bonnar). Forrest's underbite and general goofiness spelled success as he became quite popular among new fans of mixed martial arts while having a UFC career with varied success. Forrest wrote a couple bestselling books, and his underbite and everyman character continue to be popular among MMA fans.
Forrest Griffin's underbite makes for a strong chin
MMA Fighter Forrest Griffin was the light-heavyweight champion in the UFC (Underbite Fighting Championships)