Im talking about guys that if you step into the ring and have no business being in their with them, they will still try and kill you. Tyson is the obvious pick. GGG is another. He doesn’t carry anyone.
Terry Norris ... king of punching fighters - novices to top names - who were on the deck. Did it from the beginning of his career to the end. Most don't show up on Boxrec. Against Joe Walker, he not only hit him when he was on the deck, he blasted him with a rabbit punch. He even tried to hit Walker after Walker had slipped and fell to a knee earlier in the round. For some reason, never got the rep for being the complete and utter cheap shot artist that he was. This content is protected
I don't think if you can find better candidate than Bob Fitzsimmons. Most fighters struggled after killing an opponent, but Fitz seemed untouched by that. He just didn't care.
Frazier. When Lyle was a fresh pro and looking for guys to spar Futch steered him away from Joe because Joe would hurt him. He put him in with Norton instead. Foster also said something like "Joe, you nearly took him head off" after their fight and Frazier replied "well, you tried to take my title away". A caveat, though, is that Joe let Bugner off the hook when he could really have done some lasting damage. But I think he lost that edge after beating Ali. Only Ali could get the beast in him to come out by then.
Norris was known, almost from the beginning of his career, to be hot headed in the ring. The Walker fight confirmed it and the Santana fights amplified it. Being merciless and being unable to control your emotions are almost exactly opposite one another.
Tyson/Thomas had an under/over of three rounds. There was a lot of speculation that Thomas was, pre fight, having big trouble with drug addictions and thus the under went crazy (it was about the only thing that was bet on in an 80s Tyson fight). And thus Tyson dominates for a round and half, is on for an easy stoppage, and then lets Thomas off the hook (figuratively and literally) for a few rounds... It was the only time prime Tyson did not get the job done there and then, when he had his opponent in serious trouble, but it did save the casinos a fair amount of cash... Maybe it is coincidence, or maybe it is evidence that the killer instinct you talk of for Tyson, could be switched off for the right price...