Stanley Kecthel Rocky Graziano Al " Bummy " Davis Ace Hudkins Terry McGovern Frank Fletcher Chuck Wiggins to name a few.
Nobody's mentioned Joe Louis? He was all business and he never stopped punching until his business was done.
I'd certainly second Barkley. The guy had no 'Off' switch. I seem to recall a story about him playing a part in Micky Rourke's movie, Homeboy, and reportedly giving Rourke a genuine paneling, during one of the boxing scenes they filmed together.
Foreman. Pre comeback he was scary. I don’t know what Joe Roman did but for a guy who shouldn’t have been allowed in the same town never mind ring big George certainly had it in for him. He was literally trying to decapitate him in there including hitting him when he was down. He was so emotionless when doing it, absolutely scary.
He did it to Leonard as well. He could comfortably been DQ’d for that one too. It wasn’t much different from the Walker one. Norris did some dumb crap in the ring.
Frazier obviously gave no quarter nor asked for it. Like Dempsey he was known to be rough sparring but with that style there isnt much choice. IMO I believe Frazier really loved combat plain an simple. That being said he showed Quarry mercey in there second fight when he tried to get Louis to stop it twice and even tried to get him out with body shots after Louis ignored him the first time. I believe he stepped off the gas when he had Bugner hurt too. Just my observation
I think he mellowed quite a bit after FOTC. And what he had left of that cold fury was reserved for Ali.