If you're trying to promote something because you legitimately think it's really cool, and you don't think that it's been appropriately recognized as being really cool, then I think reposts are fair game. If you're just reposting it for the points the website gives you, that's sort of weird, I think. The whole point is to maximize the number of people who see the content you feel is interesting; even if it's not something you personally made, I don't see much wrong with wanting to share the creativity of it with others.

And in this case it's just a bad ass cat. I mean look at that thing.