Limiting it to mammals underrates the animal kingdom somewhat.
I would say an 8 metre saltwater croc would have a great chance against prime Ali, so would a 6 metre great white shark - especially if the bout was staged in a submerged ring...
Originally Posted by Luigi1985
Nobody would beat a prime Ali. In the 60s, he was unbeatable. OK, he was KD and almost KOŽd by Cooper, but only because he fooled around. Against Banks also. Against Doug Jones, he was too green, and btw, he had a headache and so, a healthy version would have KTFO Jones. I would only favour slightly some really big mammals (Polar Bears, Sibirian Tigers, etc.), but humans? No way in hell... Ali, his opponents, and the whole era were clearly the best ever, in every single category!