"Well, I'm a skeleton," Papyrus repeats, a little dryly. He doesn't mind any rudeness in the question - he and friends of his ask bluntly direct questions like that all the time - but because the answer seems obvious. But, you never know, so it's worth repeating.

And, because he's had this basic conversation a few times, he clarifies; "A skeleton monster. The monster is the important part, I'm not a dead human."

He makes a face at the last bit. Zombies are gross - certain friendly undead mice and birds being the exceptions.