Interspecies Conflict/Fights and more fights
Here are some.
1: Game-bred Tosa vs. ratel at parity
2: 25 kg wolverine vs. 35 kg spotted or striped hyena
3: 20 kg game-bred pit vs. 25 kg olive baboon
4: 15 kg ratel vs 15 kg clouded leopard (both mature, prime adults)
5: Prime alpha male chimp vs. prime alpha male cougar at exact parity face to face (no ambush)
6: Boar vs. black rhino the size of the boar
7: Black rhino vs. hippo at normal weights
8: Black rhino vs. hippo at exact parity
9: Game-bred Tosa vs. spotted hyena at exact parity
10: Game-bred Tosa vs. cougar at exact parity
1: Almost impossible to say but I would imagine the ratel would have the more damaging weapons, with jaws and teeth shaped by nature and survival and dangerous claws. That should be the difference considering how durable both animals are.
2: With just 10kg I think I'd go with the wolverine. It would come at the hyena with all guns blazing. This is an animal that has been known to kill animals far bigger than itself, so despite the hyena's reputation for toughness, I think the wolverine can finish it off.
3: The pitbull has a chance simply because of its tenacity, physicality and athleticism but dog vs ape is always a bad match up. The baboon can grab the dog and inflict hugely damaging bites. Easier said than done of course, but the stories you hear from Africa seem to reflect this being what happens when dogs encounter baboons. A game pitbull is a different story of course, but life on the line, the baboon has the tools to beat any dog that isn't much bigger than it.
4: The Clouded Leopard should be too much for the ratel. It would be significantly stronger overall and has the means to deliver a killing blow.
5: Ape vs Cat at higher weights and I'll nearly always back the cat. They can just dish out too much damage too quickly and are perfectly designed killers. The chimp won't want to be involved in this fight at all.
6: Hard to say again, due to the impracticalities of scaling up/down, but maybe the rhino. Horns are such good weapons because they are so readily used. It's just there at the end of its nose so there's so it's wielded with such ease and accuracy. Then obviously it has the toughness to take a fair bit of punishment.
7: Same as above. Both extremely dangerous and capable animals but I think the rhino just has a few more tools.
8: And again. Parity favours the rhino more though.
9: At risk of encouraging the sickos who do it, these types of fights have been done. Mastiff/bull-type dogs are just too strong and skilled in wrestling for hyenas. From what I've heard, they almost never kill them, which is important, but they do dominate physically. So we'd probably have that here as well with the Tosa. But the kill is the key, because that's generally how we end these hypotheticals. If that's the case, I'll go with the hyena. It'll take all the Tosa throws at it but it won't give up. It's a survivor, and a survivor with a huge bite! When the Tosa gives up (and it will, even if it's an hour later) the hyena can swoop. And even when being dominated in a wrestler, the hyena still has the capacity to land a crippling bite.
10: Cougar for me. Similar to the chimp in that the cougar just has too many tools here. It'll rip the Tosa up as it's being wrestled on the ground and at any time it can land a killing bite. The Tosa has a better chance at lighter weights. Anything over 50kg and the cat is entering prime size where as the Tosa is getting too big to be effective.
Hope that helps mate.