Demon, Leech

Amphibious. Can breathe air and water.

Blood Sense. Can pinpoint by scent the location of creatures that aren't Constructs or Undead within 30' of it.

Magic Resistance. Advantage: spell/magic effect saves.

Multiattack. One Bite and two Tentacle Bites or two Bite attacks.

Bite. Melee Weapon Attack: +8 to hit, 10 ft., one target, 14 (3d6+4) piercing damage + 9 (2d8) necrotic.

Tentacle Bite. Melee Weapon Attack: +8 to hit, 5 ft., one target, 11 (2d6+4) piercing damage and 4 (1d8) necrotic and demon can attach its tentacle to target. Has two tentacles each of which can attach to only one target. While tentacle is attached demon can't use that tentacle to make Tentacle Bites target is restrained and demon doesn't attack with it. Instead at start of each of demon's turns each creature with tentacle attached loses 11 (2d6+4) hp due to blood loss and demon gains equal temp hp equal. Demon can add temp hp gained from this attack together and can add it to temp hp gained from Release Swarm. Demon's temp hp can't exceed half its hp max. Demon can detach one or both tentacles as a bonus action. A creature including target can use its action to detach demon's tentacle by succeeding on a DC 17 Str check.

Release Swarm (Recharge 5-6). Shakes loose dozens of leeches creating a leech swarm. Swarm acts as ally of demon and obeys its spoken commands. Swarm remains for 1 min until demon dies or until demon dismisses it as a bonus action. If demon is within 5 ft. of the swarm it can use its action to consume the swarm gaining temp hp equal to swarm's current hp. It can add temp hp gained this way with temp hp from Tentacle Bite. Demon's temp hp can't exceed half its hp max. Can have only one swarm active at a time.