Strigoi

The strigoi can magically control stirges within 120 feet of itself using a special telepathy.

The strigoi makes two Claw attacks and one Proboscis attack.

Melee Attack Roll: +5, reach 5 ft. Hit: 10 (2d6 + 3) Slashing damage.

Melee Attack Roll: +5, reach 5 ft. Hit: 5 (1d4 + 3) Piercing damage plus 7 (2d6) Necrotic damage. The target's Hit Point maximum decreases by an amount equal to the Necrotic damage taken, and the strigoi regains Hit Points equal to that amount. A creature reduced to 0 Hit Points by this attack dies, leaving behind nothing except its skin and equipment.

The strigoi summons a swarm of bloodthirsty mosquitoes in a 10-foot Emanation originating from itself, which lasts for 1 minute or until the strigoi's Concentration on it ends. Whenever the swarm enters a creature's space or a creature enters the swarm or ends its turn there, that creature is subjected to the following effect (a creature makes this save only once per turn, and strigoi and stirges are unaffected). Constitution Saving Throw: DC 13. Failure: 3 (1d6) Necrotic damage, and the target has the Poisoned condition until the end of its next turn.