Swarm. The swarm can occupy another creature's space and vice versa, and the swarm can move through any opening large enough for a tiny horror. The swarm can't regain hit points or gain temporary hit points. Blurry Presence. Creatures have a disadvantage of perception checks relying on sight on this creature. Eldritch Body. When directly touched by a creature, that creature takes 1d8 psychic damage. Veil Walk. As a bonus action the swarm can travel on the veil, disappearing from the material world. They can move through objects and creatures as if they were difficult terrain. This ends at the start of their next turn.
Bites: Melee Weapon Attack: +6 to hit, reach 0 ft., one creature in the swarms space. Hit: 10 (2d8) psychic damage, or 5 (1d8) psychic damage if the swarm has half it's hit points or fewer. The target must make a DC 10 intelligence saving throw, taking 14 (4d6) psychic damage on a failed save, or half as much on a successful one.