For a short time between 2009 and 2010, Shaquille O’Neal had his own TV show for ABC, Shaq Vs., on which he would challenge other professional athletes from different sports to events pertaining to said sport.
One of the NBA Hall of Famer’s “opponents” was Michael Phelps, who is widely considered the best swimmer of all time. (He’s certainly the most decorated one.)
Though the network gave Shaq a bunch of handicaps to help even the playing pool (sorry), Phelps ultimately showed that he’s basically a merman.