Mike Tyson bit Evander Holyfield.

The biting incident

During their 1997 rematch for the WBA heavyweight title in Las Vegas, Tyson twice bit Evander Holyfield’s ears during the third round, tearing a piece from Holyfield’s right ear and later biting the other ear in a clinch. The bout was stopped and Tyson was disqualified, and the incident became one of the most infamous moments in boxing history.