Answer:
Mike Tyson bit Evander Holyfield's both the ear’s in a bout during a match known as Holyfield–Tyson II. He bit Holyfield’s ear twice and the second time he took a small chunk out of it. This happened on June 28 1997 at the MGM Grand Garden Arena in Las Vegas, Nevada.
During the third round with forty seconds remaining in the round Holyfield got Tyson in a clinch and Tyson reacted to this approach of Holyfield by biting his right ear. Later on he bit the left ear as well.
Tyson lost as he was disqualified. His boxing license was revoked temporarily by the Nevada State Athletic Commission. Additionally he was fined USD $3 million plus legal costs.
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