Actions/Abilities/Traits: (D&D 5e)
Action
Mass of Tentacles
Melee Weapon Attack: +6 to hit, 0 ft. reach, two targets in the swarm's space. Hit: 21 (6d6) poison damage. If the target was a creature it must succeed a DC 15 Constitution saving throw or be poisoned for 1 minute.
Special
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 jellyfish. The swarm can't regain hit points or gain temporary hit points..
Special
Water Breathing
The jellyfish swarm can only breathe underwater.