Gren the Gormless Ghast

Ghasts in general fall somewhere between the undead in possession of a decaying body and ghosts who are possessed of nothing corporeal. They are marked as being significantly more wily than zombies, and capable of setting traps for their unwary prey. To be called a ghast is to mark something as more dangerous than a mindless ghoul.
Gren the Ghast, a denizen of the Forest of Pain, does not entirely fit this description. At all. He's rather stupid, and the only reason he's survived thus far is because his stupidity keeps him close to his original gravesite, and because his nearly indestructible nature makes him an ideal test for aspiring young warriors to practice against the necromantic subgenre.
The only reason he's not simply called a zombie is because Gren is rather tall and thin and he does possess the claws that most ghasts have.