Swarm of Centipedes

The swarm can occupy another creature's space and vice versa, and the swarm can move through any opening large enough for a Tiny insect. The swarm can't regain hit points or gain temporary hit points.

+0 to hit. Hit: 5 ((4 - (@statuses.bloodied * 2))d4) piercing damage. Melee Weapon Attack: , 0 ft., one creature in the swarm's space. Hit: damage, or damage if the swarm has half of its hit points or fewer. A creature reduced to 0 hit points by a swarm is stable but poisoned for 1 hour, even after regaining hit points, and paralyzed while poisoned in this way.