Baldur's Gate Wiki

IMMCLOUD.ITM is an undroppable item equipped in a necklace or amulet slot by certain creatures, such as some familiars and Mephit creatures. the item provides particular immunities while worn, including:

Level drain effects
Sleep (Status Effect) as well as Power Word, Sleep, and also any effect that makes one Unconscious.
Petrified effects of all types and sources.
Cloud Projectile (projectile No. 94). Any spell, wand, trap, creature or innate ability that launches this projectile will not affect the creature.

It has no animation assigned. The item has no other powers or abilities.