Bag of Rats (Patreon)

Adventuring gear, uncommon

This small leather bag is filled with rat bones and magic herbs used in necromantic rituals. As an action, you can sacrifice 1d4 hit points and speak its command word to summon a number of Ghost Rats equal to the damage taken. As long as the rats are summoned, your hit point maximum is decreased by the amount of necrotic damage taken.

They are friendly towards you, you are treated as their ally, and they’ll obey all your commands to the best of their abilities. After 1 hour, they return to the bag and vanish. You can’t summon other rats as long as the previous ones are still active. Once the rats vanish, your mind is filled with all they have seen and heard.

The Ghost Rats use the Rat stat blocks, except they are undead in addition to its other types and have the Incorporeal Movement trait.

Incorporeal Movement. The ghost rats can move through other Creatures and Objects as if they were Difficult Terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.