Jay Dee Penn goes by the name BJ (baby Jay) due to being the youngest of his siblings all sharing the same name.

Penn is nicknamed 'The Prodigy' with good reason - the first ever American born winner of the Mundials in the black belt category after it took him only three years to reach the grade, an unbelievable feat in itself.

Penn went on to be successful in MMA and was only the second person to hold UFC titles in two weight classes (lightweight and welterweight). He has also been known to challenge himself against much larger opposition - going from lightweight all the way up to a heavyweight contest with current light-heavyweight champion Lyoto Machida. Penn lost via decision in a valiant effort.

He holds notable wins over Matt Hughes, Takanori Gomi, Renzo Gracie, Sean Sherk and Kenny Florian.

He was dominating the UFC's lightweight division until Frankie Edgar edged him out at UFC 112 in Abu Dhabi. With the fight being so close, Penn was offered an immediate rematch but lost in more convincing fashion at UFC 118.