Swarm of Chorister Bees (5e Creature)
From D&D Wiki
Swarm of Chorister Bees
Huge swarm of Small beasts, unaligned
Damage Resistances bludgeoning, piercing, slashing
Innate Spellcasting. The swarm's innate spellcasting ability is Charisma (spell save DC 14). It can innately cast the following spells, requiring no components:
Swarm. The swarm can occupy another creature's space and vice versa, and the swarm can move through any opening large enough for a Small bee. The swarm can't regain hit points or gain temporary hit points.
Stings. Melee Weapon Attack: +8 to hit, reach 5 ft., one creature. Hit: 18 (4d6 + 4) piercing damage, and the target must make a DC 10 Constitution saving throw. On a failed save, it takes 14 (4d6) poison damage plus 14 (4d6) psychic damage, or 7 (2d6) poison damage plus 7 (2d6) psychic damage if the swarm has half of its hit points or fewer, and becomes incapacitated with pain until the end of its next turn. On a success, it takes half as much damage.
Bees the size of dogs, each marked with a blazing sigil. They don't buzz, but sing in
plainsong. The thrashing of their wings is the drumbeat of apocalypse, and people flee in panic from their mighty stingers.