Looks like a mummified monkey to me. Any aliens who had the brainpower to travel from their home planet, that is likely light years away from us, would probably not leave their young ones on Earth to be killed by a RAT TRAP. Honestly, if you were to travel to an entirely different planet, would you just leave your kids there, entirely unprotected and vulnerable to eventual traps set by the inhabitants? It's just so illogical that i can't bring myself to believe it. I could be wrong, but i want concrete proof that it isn't just an oversalted monkey or whatever odd creatures we have on Earth.
Even if it was a fully grown alien, it still doesn't make sense to just roam around unprotected on an alien planet. One should think that interplanetary (or even intergalactic) travellers would carry at least a little bit of equipment for self-defense and what not.
TL;DR: I don't believe it, but i don't exclude it entirely. I just want concrete and infallible proof.