Stirge
Tiny beast, unaligned Armor Class 14 (natural armor) Hit Points 2 (1d4) Speed 10 ft., fly 40 ft.
STR DEX CON INT WIS CHA
4 (−3) 16 (+3) 11 (+0) 2 (−4) 8 (−1) 6 (−2) Senses darkvision 60 ft., passive Perception 9 Languages — Challenge 1/8 (25 XP)
Actions
Blood Drain. Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 5 (1d4 + 3) piercing damage, and the stirge attaches to the target. While attached, the stirge doesn’t attack. Instead, at the start of each of the stirge’s turns, the target loses 5 (1d4 + 3) hit points due to blood loss. The stirge can detach itself by spending 5 feet of its movement. It does so after it drains 10 hit points of blood from the target or the target dies. A creature, including the target, can use its action to detach the stirge.