Even when considering Brock Lesnar’s NCAA wrestling pedigree, his herculean strength, and freakish athleticism, many remained convinced that a man who made his mark as a pro wrestler in the WWE would amount to nothing in the malevolent world of mixed martial arts… but they were wrong.
With a swiftness bewildering for a man his size, Lesnar tore through his first opponent, Moo Soo Kim, with a level of speed and force that mirrored his ascension to the very pinnacle of the sport.
As history would have it, Lesnar would go on to become the UFC Heavyweight Champion at UFC 91 and defend his title before eventually succumbing to Cain Velasquez at UFC 121. He announced his retirement due to pervasive and continuing health problems not long thereafter.
Brock Edward Lesnar is an American professional wrestler, mixed martial artist, and former amateur wrestler and professional American football player. He is currently signed to WWE. Lesnar is a four-time WWE (World Heavyweight) Champion, a former UFC Heavyweight Champion, and an NCAA Division 1 Heavyweight Wrestling Champion. He is also a one-time IWGP Heavyweight Champion, making him a five-time world champion in professional wrestling.
Though Lesnar said he was "closing the door on MMA" in March 2015, UFC announced on June 4, 2016, that he would return at UFC 200 on July 9. WWE confirmed it had granted Lesnar "a one-off opportunity" to compete at UFC 200 before he would return to the company for SummerSlam on August 21. [Source: wiki]