Yes, I'm up for that. Seriously though, as far as I'm aware, humans are the only species on this planet that likes to hunt, maim and kill other animals just for fun. People who do that have to be psychotic - it has to take a total lack of empathy to be able to do that I reckon.
I don't think that's strictly true. Cats will kill birds, and then not eat them. They often present them as presents to their human "owners'. With a bit of thought, I suspect a naturalist would be able to come up with lots of examples like that.
One could argue that they are doing that out of an innate urge to maintain their hunting skills. But then, the same argument could be applied to the bozos that hunt lions.
Also, many flocking birds will kill other birds of the same species if they are not originally from the same flock. In the latter case, one could argue that they are doing it out of a vague sense of protecting the flock, but from a philosophical point of view, when does that become morally unacceptable? Killing a bird that has joined the flock is like a human killing an immigrant. The rejoinder is that birds don't have such a refined ethical sense as us. But then, that is an argument for not comparing humans to animals in the first place, when making moral arguments.
I'm not defending the hunting of big game: I think that it's an awful way to get one's 'kicks', and I am revulsed by it. But I don't think recourse to a comparison with the animal kingdom is the right argument: I think a better argument is that the whole point of human civilisation is to act as a check on the baser animal instincts that we might still have. Which is why we have concepts such as justice, fairness, not abusing those who are weaker than us, etc.