In 2003 and 2004, WWE Superstar Zach Gowen proved his fearlessness by competing in a WWE ring and even standing up to Mr. McMahon – something few Superstars have ever dared to do. Gowen was a unique Superstar because he competed with only one leg. Losing his limb to cancer as a child never stopped him from pursuing high-stakes competition, which he proved when he recently took on the daunting "American Ninja Warrior" obstacle course.

Watch the video below to see Gowen's impressive performance.