B.J. Penn is a retired American mixed martial artist and Brazilian jiu-jitsu practitioner, widely regarded as one of the greatest fighters in the history of the sport. Born on December 13, 1978, in Kailua, Hawaii, he became the first fighter in UFC history to win titles in two different weight classes: UFC Lightweight and UFC Welterweight. Penn is known for his exceptional grappling skills and striking ability, earning him the nickname "The Prodigy." Throughout his career, he competed against many top fighters and was inducted into the UFC Hall of Fame in 2015, solidifying his legacy in mixed martial arts.