That would have to be Cassius Clay aka Muhammed Ali.
Bob Dylan is the correct answer
The cast of The National Rash - 1924 includes: Walter Hagen as Himself - Golf Champion Gene Sarazen as Himself - Golf Champion Jess Sweetser as Himself - Golf Champion
The cast of TV Champion - 1999 includes: Misao Fujita as himself Takeru Kobayashi as himself Eigo Okuno as himself Masahiro Tateishi as himself
The cast of Elements of a Champion - 2004 includes: Bay Bay McClintock as himself Daunte Culpepper as himself Priest Holmes as himself Steve McNair as himself Randy Moss as himself Terrell Owens as himself LaDainian Tomlinson as himself
The cast of Weekend of a Champion - 1972 includes: Joan Collins as herself Graham Hill as himself Roman Polanski as himself Ringo Starr as himself
The cast of Once a Champion - 1991 includes: Dwight Muhammad Qawi as himself Matthew Saad Muhammad as himself
The cast of Once I Was a Champion - 2011 includes: Randy Couture as himself Rich Franklin as himself Forrest Griffin as himself John Herzfeld as himself Matt Lindland as himself Benji Radach as himself Bas Rutten as himself Chael Sonnen as himself Evan Tanner as himself
Gene Sarazen has: Played Himself - Golf Champion in "Screen Snapshots, Series 4, No. 2" in 1923. Played himself in "Golf, as Played by Gene Sarazen" in 1923. Played Himself - Golf Champion in "The National Rash" in 1924. Played himself in "Building Winners" in 1924. Played Himself - Golfer in "Traps and Troubles" in 1925. Played himself in "Toast of the Town" in 1948. Played Himself - Golfer in "When Sports Were King" in 1954. Performed in "Golf: The Greatest Game" in 1994. Played himself in "ESPN SportsCentury" in 1999.
Do Sheamus's ENTIRE RTWM story;One night they'll come and Sheamus will declare himself the European Champion not the US champion
The cast of Weekend of a Champion - 2013 includes: Roman Polanski as himself
The cast of Soul of a Champion - 2006 includes: Martin Brodeur as himself
Joey Chestnut has: Played Himself - Interviewee (hotdog eating champion) in "Newsround" in 1972. Played himself in "Weekend Today" in 1987. Played Himself: Professional Eating Champion in "Modern Marvels" in 1994. Played Himself - Eating Champion in "Mike and Mike in the Morning" in 2005. Played himself in "Man v. Food" in 2008. Played himself in "Shaq vs" in 2009. Played himself in "Hungry Girl" in 2011. Played himself in "Hotel Impossible" in 2012.