not any skeleton but an animal skeleton, so you can be anything that has a skeleton so you can be Spoiler: a penguin skeleton Spoiler: t rex skeleton so what would you be? Spoiler: my answer POLAR BEAR They have a dick bone
I'm not sure what the point of being a skeleton would be. But mammoths are cool, just to have that on the record.
Frankly, there is no point in being a bird or fish skeleton, since you can't fly or swim if you are just bones. But you can walk/run. And four legs is a win on land. So the only real option is to be a land mammal. I personally would go for monkey bones (macaques/orangutans etc) due to the opposable thumb and all. As for reptiles, well the reptiles have some great advantages over mammals, which are all lost as a skeleton, like sticky feet, camouflage, transparent eye lids, etc.
no skeleton yes, you are an animated skeleton capable of movement without muscle, fluid dynamics isn't really high on your priorities
It's an exo-skeleton, although it's not quite the same, it could still count but it'd be like being an empty armour.