The gastly (sub-species of zombie) is a playable race specific to Slash'EM Extended. They can be any role and alignment, and they start with intrinsic cold resistance, sleep resistance, poison resistance, sickness resistance and unbreathing. Gastlies are also undead and mindless, and they can only eat old corpses. In melee combat they have a chance of paralyzing an enemy. Their maximum stats are as follows:
Despite their load of starting intrinsics and special melee attacks, gastlies are hard to play. They start with some fresh corpses in their inventory which will eventually go bad (unless they're lichen), allowing them to be eaten, and if the player's role would start out with food rations, they will get converted to corpses too (sometimes boosting starting strength or constitution to allow the player to carry all of them without being burdened), but they will only give so much nutrition, after which the player needs to find more corpses. Then the player needs to prevent pets from eating the fresh corpses; one way of doing that would be picking them up, but some filling monsters like centaurs and dragons weigh a ton.