Jens Johnnie Pulver (born December 6, 1975) is an American professional mixed martial artist and undefeated boxer and kickboxer. Pulver was the inaugural UFC Lightweight Champion in addition to serving as the headcoach on the The Ultimate Fighter 5 reality show against long-time rival B.J. Penn. In mixed martial arts, Pulver competed at the Lightweight, Featherweight, Bantamweight and Flyweight divisions in addition to competing at the Middleweight, Light Middleweight, and Welterweight divisions as a professional boxer. While perhaps best known for competing in the UFC, Pulver has also competed in Pride Fighting Championships, for the PRIDE 2005 Lightweight Grand Prix. He is to-date the youngest UFC Lightweight Champion in the UFC history, eventually relinquishing his title, after two defenses, due to a contract dispute. Pulver officially retired from combat sports in 2014. Pulver is considered the founder of the UFC lightweight division.