Bone Faerie

Shapechanger. The Bone Faerie can use its action to polymorph into a beast form that resembles a hummingbird (speed 0 ft., 120 ft.), an owl (20 ft., fly 60 ft.), or a frog (20 ft., swim 20 ft.), or back into its true form. Its statistics are the same in each form, except for the speed changes noted. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: (1d4 + 2) piercing damage, the bone faerie is healed for half damage dealt. The target must succeed on a dc 11 constitution saving throw or become poisoned for 1 minute If the saving throw fails by 5 or more, the target falls unconscious for the same duration, or until it takes damage or another creature uses an action to shake it awake.

Invisibility. The bone faerie magically turns invisible until it attacks or until its concentration ends (as if concentrating on a spell). Any equipment the bone faerie wears or carries is invisible with it.