Grasping Tentacles. All over the creature's body grow tentacles of up to 25 feet in length. A darktentacles commonly has enough tentacles to contend with multiple opponents simultaneously. They may slap, grasp, and constrict opponents, or wield weapons. Each tentacle is AC15, and is immune to psychic and poison damage. Attacks against tentacles that do at least 5 damage cause them to let go. 10 or more damage severs a tentacle. Destroying tentacles does no damage to the darktentacles.

Predatory Senses. Each tentacle is studded with many small, shielded nodes that see as humans do, but also have darkvision. A darktentacles also senses vibrations, "smells" substances in water, and discerns color and light differences through nodes all over its body.

Multiattack. The darktentacles uses Constrict. It can then simultaneously battle as many opponents as it can reach. Each opponent may be attacked by up to 5 tentacles at a time, or 2 tentacles at a time if they are wielding weapons (weapons deal their normal damage).

Constrict. The darktentacles deals 8 (1d6+5) bludgeoning damage to each creature for each tentacle grasping it. It then pulls each of those creatures 10 feet straight toward it.

Tentacle. Melee Weapon Attack: +9 to hit, reach 25 ft., one target. Hit: 7 (1d4+5) bludgeoning damage or it can grasp a target. Creatures grasped by 1-2 tentacles are grappled (escape DC17), 3-4 tentacles cause the creature to become restrained, and 5 tentacles will make a creature incapacitated.

The darktentacles can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The darktentacles regains spent legendary actions at the start of its turn.

Tentacle Attack. The darktentacles makes one tentacle attack.

Move. The darktentacles can move up to its swim speed.