Astral Blight Swarm

Illumination. While it has at least 1 hit point, the astral blight sheds dim light in a 10-foot radius.

Unusual Nature. The blight doesn’t require air or sleep.

Swarm. The swarm can occupy another creature’s space and vice versa, and the swarm can move through any opening large enough for a single astral blight. The swarm can’t regain hit points or gain temporary hit points.

Multiattack. The blight makes two Heat-Draining Vine attacks.

Heat-Draining Vine. Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 15 (3d6 +4) radiant damage, and if the target is a Large or smaller creature, it is grappled (escape DC 13). Until this grapple ends, the target takes 7 (2d6) cold damage at the start of each of its turns. The blight swarm has four vines, each of which can grapple one creature.