Stirge

Tiny Monstrosity, Unaligned

AC 13 Initiative +3 (13)
HP 5 (2d4)
Speed 10 ft., Fly 40 ft.

Senses Darkvision 60 ft.; Passive Perception 9
Languages None
CR 1/8 (XP 25; PB +2)

Actions

Proboscis. Melee Attack Roll: +5, reach 5 ft. Hit: 6 (1d6 + 3) Piercing damage, and the stirge attaches to the target. While attached, the stirge can’t make Proboscis attacks, and the target takes 5 (2d4) Necrotic damage at the start of each of the stirge’s turns.
 The stirge can detach itself by spending 5 feet of its movement. The target or a creature within 5 feet of it can detach the stirge as an action.