A skeleton is a type of physically manifested undead often found in fantasy, gothic, and horror fiction, as well as mythology, folklore, and various kinds of art. Most are human skeletons, but they can also be from any creature or race found on Earth or in the fantasy world.
Many different types of skeletons in the games I play are pretty awesome. Only problem is the ambushing from the Minecraft skeletons, but hey, they're supposed to do that.