Nope, they've already gone over this whole thing at Zelda Informer.
That's not Skull Kid, people. It's a Skulltula (ya know, the spider). It's just hanging from the ceiling, and those little things you see sticking out underneath its body are its legs. The design on the body is the same design as the Skulltula that appeared earlier on in the trailer (the one that Link killed).
Sorry people, but it's just a bug.