Kenneth Wayne Shamrock is an American bare-knuckle boxing promoter, professional wrestler, and retired mixed martial artist and kickboxer, currently signed with Impact Wrestling. A UFC Hall of Fame member, Shamrock is widely regarded as one of the greatest fighters in the history of MMA, as well as an icon and pioneer of the sport. He has headlined over 15 main events and co-main events in the UFC and Pride FC and set numerous pay-per-view records. In the early part of his UFC career, Shamrock was named "The World's Most Dangerous Man" by ABC News in a special called "The World's Most Dangerous Things". The moniker has stuck as his nickname.

Shamrock became known early on in the UFC for his rivalry with Royce Gracie. After fighting to a draw in the inaugural UFC "Superfight", he became the first UFC Superfight Champion when he defeated Dan Severn at UFC 6; the title was eventually replaced by the UFC Heavyweight Championship when weight categories were introduced to the UFC. He was also the first foreign MMA Champion in Japan, winning the title of King of Pancrase. During his reign as the UFC Superfight Champion, he was widely considered the #1 mixed martial artist in the world. In 2008, Shamrock was ranked by Inside MMA as one of the top 10 greatest mixed martial arts fighters of all time. He is the founder of the Lion's Den mixed martial arts training camp, and is the older brother of Frank Shamrock.