Troll Limb

A troll limb as ally is a stretch, but a useful one for a campaign with a hag patron, a flesh-witch wizard, or a dwarven war-surgeon researching regeneration. The framings that hold up: a witch has bound the limb with a thumb-tied ribbon as a crawling familiar, the party has been gifted one as a magical relic by a creature that wanted them to remember a debt, or a court alchemist is paying the party to keep one alive in a brass cage for a month.

Use the limb out of combat as a horror prop with utility. Troll Spawn keeps it linked to a distant parent troll's senses, which means the limb can hear and feel from the same range; with the right ritual binding (a hook the GM can hang a quest on), the bound limb relays what the parent troll experiences. Regeneration of 5 HP per turn means the limb survives most environmental hazards the party would rather not test in person. Drop it down a pit to confirm there are spikes. Send it across a bridge to find the trap.

In combat it is a 14-HP, AC 13 distraction with a +6 Rend for 9 average. Position it on the enemy's flank, where its 20 ft. walk speed can reach a back-line caster after one round of movement. Regeneration carries it through one or two enemy hits as long as no torch or acid flask hits it. Recall it before the party rests; a forgotten limb is a betrayal contract waiting to mature.

What the limb refuses: nothing. It has 1 Intelligence and no will. The handler is responsible for the harm it causes.

Roll the Troll Spawn d12 every dawn the limb is alive in the open. The first 12 the party sees changes the campaign.

A troll limb is the encounter that happens after the troll fight ends without fire or acid. The party hacked off an arm with a longsword, kept fighting the body, and walked away three rounds later thinking the corridor was clear. Then the arm starts dragging itself toward them. Run the limb as a horror beat first and a combat threat second.

Mechanically the limb is a small Giant with 14 HP, AC 13, walk 20 ft., Darkvision 60 ft., and a single Rend attack at +6 for 9 average slashing. It is not going to win a fight. What it does is regenerate 5 HP at the start of each of its turns, and it dies only if it starts a turn at 0 HP without regenerating. Acid or Fire damage shuts off Regeneration for one turn. Without that, every PC swing just resets the timer. A wizard with a Fire Bolt cantrip ends the limb in two rounds. A barbarian with no fire option fights it forever.

The placement is the encounter. Have the limb crawl out of a sack a player slung over their shoulder, drop from a chandelier where it has been clinging, or wait under the bed at the inn the party booked after the fight. Troll Spawn means the limb shares the parent troll's senses, so it knows where the party is, and a 1-in-12 chance per limb of becoming a full Troll after 24 hours means an unlucky party finds a CR 5 monster in their stable. Roll the d12 in the open the morning after.

The limb does not retreat. It does not feel pain. It will keep crawling until burned. If the party leaves it in a closet and runs, the closet has a Troll in it next session.

Describe the limb's first move with one specific image: a finger twitching, a tendon flexing, a stump dragging across stone. The horror is the silence before the rolling resumes.