A skeleton is a magically animated undead creature that appears in Nethack.
Skeletons have a slowing attack that can remove intrinsic speed; chatting with a skeleton, even a tame one, will paralyze you for a few turns. They have immunities to cold, sleep, poison, and stoning.
Skeletons are only randomly generated in Orcus Town, and they are valid targets for polymorph traps and the summon nasties spell. Polypiling multiple objects made of bone, such as unicorn horns, may also create a skeleton.
While skeletons are not a great threat at the point they are encountered, especially given the presence of shades, their ability to nullify speed still means they should not be overlooked. Their stoning resistance means that they can wield footrice corpses, so be careful leaving them around Orcus Town.
A skeleton is a magically animated undead creature. Unlike
shades, only a humanoid creature can be used to create a
skeleton. No one knows why this is true, but it has become
an accepted fact amongst the practitioners of the black arts.