[nomel]

Leopards can't begin to approach what a monkey can do [1], since they can't hang safely, since they don't have thumbs. Leopards rely on penetration of their claws, or being on top of the branches, like squirrels. It works for the squirrel because they're small, and the tension forces applied to the bark are negligible, so they can just crawl upside down. You won't see a leopard hanging from anything, in a non-comical way. A leopard does have an advantage of clawing up thick trunks, which is one of the reasons they hunt monkeys that are first on the ground, rather already in the trees.

[1] https://youtu.be/9rdn26Hpdwo?feature=shared&t=118

[jvanderbot]

Speaking of hanging, you know who really climbs trees well though? Sloths. Great at hanging. Practically live up there.

No thumbs.

[nomel]

Yes great at hanging, like a coat hanger. You can only easily pull with a hook. With a thumb, you can push, pull, and easily grip, with much less risk of "unhooking". That's the same risk for a leopard: unhooking. Sloth can't climb a thinner vertical rope, or hang from a thinner branch, because their grip strength is relatively weak, due to the leverage. And, good luck using any sort of tool, like a stick to get terminates, with giant hooked claws!