Shamblings Skeletons are melee enemies who suffer bone decay and reduce intelligence. They blindly run at any living humans and attack with their arms. Losing the ability to speak, they have devolved to only grunt. If they can't reach their intended target, they will grab onto their ribs and tear out a fragment and throw it at their victim.
These Skeletons are amongst the easiest to cripple as they have no armor on any limb.
Trivia
Their grunts and moans share the same with Zombies.