uruzrune

When crit, does its remaining HP in damage to all adjacent creatures, half on a DC 10 DEX save. Then, the Mutant dies.

Starting turn at 5 HP or less: The Mutant does not move or take an action. At the beginning of its next turn, Mutant's HP resets to maximum and then goes Splat!

Cannot be hit or damaged.

The gremlin is dispelled by sacrificing one or more exceptional crafted items. A separate sacrifice must be made for each gremlin.