Brock Lesnar is a wrestler.
Brock Edward Lesnar ( [ ˈlɛznər ] born July 12 , 1977 ) is an American professional wrestler and former mixed martial artist , amateur wrestler , and professional American football player . Lesnar won the then WWE Undisputed Championship five months after his main roster debut at the age of 25 , becoming the youngest champion in the title 's history . The IWGP Heavyweight Championship was a professional wrestling heavyweight championship used by the Inoki Genome Federation ( IGF ) promotion .