13. Sonny
“Sonny Liston. There was something really horrific in him. His eyes, the way he walked, and the way he talked,” TwoFaceLord wrote on Reddit. “Dude was straight-up scary. Plus his arms were freakishly long.” At the end of the day, Liston was one of the most enigmatic and intimidating boxers of his era. He had longstanding connections to the mafia and underground crime groups which gave him a fearsome mystique.

Then there is his body of work inside the ring. Yes, Cassius Clay defeated him but before this, he seemed unbeatable. 39 of his 50 wins came by way of knockout. Meanwhile, he also served a six-month prison sentence after brutally beating up a police officer in 1956. Liston was as hardcore and intense as they came but also a brilliant boxer in his heyday.