Cursed Keese (5e Creature)
From D&D Wiki
Tiny undead, neutral evil
Dark Cloak. The cursed keese’s body is eternally burning with magical darkness, which out to a range of 5 feet makes dim light dark, and makes bright light dim light. Any creature which directly touches it takes 2d6 necrotic damage, and is incapacitated until the end of its next turn.
Undead Fortitude. If damage reduces the cursed keese to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant damage or from a critical hit. On a success, the cursed keese drops to 1 hit point instead.
Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 1 piercing damage, and the target is exposed to the keese’s dark cloak.
The body of a cursed keese is that of an animated bat skeleton, wrapped in blackish violet flames, and glaring with glowing yellow eyes.
Undead Nature. A cursed keese does not require air, food, drink, or sleep.