Ultimate Fighting Championship (UFC) is the largest Mixed Martial Arts (MMA) organization in North America. It started as an 8-man tournament back in 1994, and Royce Gracie won the first several tournaments. One of the first break-out stars of UFC was Ken Shamrock, who was billed as "The World's Most Dangerous Man" on NBC, and then he signed a contract with the World Wrestling Federation. Dan "The Beast" Severn was another standout signed to the WWF.
Eventually, UFC started adding special "Super Fights" to sweeten the cards, and then the Super Fights replaced the tournament format. Nowadays, the UFC host pay-per-view events (about 16 annually, which is way too many for their current roster) featuring 6-9 matches, usually headlined by a championship match or an important rematch. One of their biggest draws is Brock Lesnar.