Mummy Hands

Little scuttling horrors. Disembodied hands skittering and leaping -- grasping, driving fingers into flesh with ab-human strength. 

They look like Thing but fill a niche with the face-hugger, the headcrab and the rot grub. An ambush, nuisance monster. Individually weak but very deadly if they slip past your defenses. 

Addams Family (1964)

Stat Line - HP: 1, AC 13, To Hit: +3, DMG: 1d4 + Attach.

If a mummy hand successfully attacks, it will puncture it's fingers into the victim's body (dealing 1d4 damage immediately) and grip onto something internal. When attached:

• The victim is infected with Grave Rot, no save (as if bit by Zombie)
• The victim will take d4 damage every hour 
• Extracting the hand requires a crude surgery. The easiest way is to cut the fingers off and pull them out individually with pliers. With proper tools and an uninterrupted hour, this can be done without causing further injury.

Grave Rot: Every hour, lose 1/4 of your max HP. Hit points lost in this way can't be healed until the disease is cured. If you die while under the effect of Grave Rot, you'll return as a zombie (or occasionally some other undead).

Grave Rot spreads from the point of infection. If it's on a limb, quick amputation can be a viable cure.

Encounters:

• Treasure chest - When the lock is turned, the lid springs open releasing a swarm of mummy hands
• Burial chamber, the walls lined with urns - Breaking any urn releases a mummy hand
• Sagging ceiling, scuttling sounds - The plaster above collapses and mummy hands rain down
• Necromancer with a belt pouch - Every round he pulls a mummy hand from his pouch and throws it at a nearby foe
• Rival adventure's corpse is found with a grotesque, withered hand gripping one of it's ribs - In 1d4 round this body will rise as a zombie. 
• Pit trap - Near the bottom, mummy hands hide in wall niches
• Stowaway - A clever hand hides in adventurer's backpack and springs when equipment is retrieved
• Wedged door, resting adventurers - A mummy hand squeezes through the crack under the door

Henson's "Helping Hands" from Labyrinth