Stipe Miocic is the undisputed heavyweight champion of the Ultimate Fighting Championship (UFC). He is the first fighter to ever defend the heavyweight title three times in a row, and he holds the record for most heavyweight title defenses. Miocic
From Wikipedia
Stipe Miocic is an American former professional mixed martial artist who competed in the Heavyweight division of the Ultimate Fighting Championship (UFC), where he is a former two-time UFC Heavyweight Champion. He is widely regarded as the greatest UFC heavyweight of all time.