Which animals show wrinkles as a sign of age?

See subject. We do. The thought came to me while looking at goldfish in a tank. “How old are you, little fishie,” I asked, and tried to figure it out.

Fish don’t get wrinkles as they get old. Right?

All animals with skin will lose elasticity with age. My old dogs both had visible drooping, sagging and wrinkling of various areas; it was less obvious than it is on people, because they have fur.

The furrier, and fattier, the mammal, the less it will show. Also some species have tighter skin naturally. I don’t think old whales and hippos ever look wrinkly. Whereas domesticated cats start out in a skin bag which only gets baggier with time (see pics of hairless cats).

I asked an elephant how old he was, he couldn’t remember.

True. Except for those darn fishies. And certain celebrities and actresses.

Wow, these dogs must be ancient! Also this guy!

I couldn’t find a photo of what I mean,* but as a dog owner I’ve always associated a big hanging bunch of skin under the sack where a neutered cat’s balls were–I think that’s what I’m seeing–with age.
*Yes, I could not find the right photo of a cat, for crying out loud, on the Internet. Water, water everywhere and all that.