Nilbog

Nilbogs are goblins possessed by trickster spirits, the result of a condition known as nilbogism. A possessed goblin tends to be a prankster and impish creature, capable of affecting the behavior of those surrounding it and of sowing chaos among its allies and enemies alike.
When struck by any harmful attack, a nilbog instead heals. Moreover, any attempt to harm a nilbog risked the attacker falling victim to nilbogism, becoming compelled to praise the nilbog instead of attacking it. Adventurers might feel compelled to hand over all their possessions to a nilbog.
The goblins believed that the nilbog spirits were fragments of a trickster deity in the goblin beliefs,