Beezlebub

Devil's Sight. Magical darkness doesn't impede Beezlebub's darkvision.

Innate Spellcasting. Beezlebub can cast the Blink spell at will without the use of spell components.

Magic Resistance. Beezlebub has advantage on saving throws against spells and other magical effects.

Shapechanger. Beezlebub can use his action to polymorph into a beast form that resembles a rat (speed 20 ft.), a raven (20 ft., fly 60 ft.), or a spider (20 ft., climb 20 ft.), or back into his true form. His statistics are the same in each form, except for the speed changes noted. Any equipment he is wearing or carrying isn't transformed. He reverts to his true form if he dies.

Voidfire Missile. Ranged Spell Attack:  +6 to hit, range 120 ft., three missiles, Hit: 6 (1d4+3) necrotic or fire damage. Beezlebub has advantage on the attack roll if any of his targets are in dim light or darkness.

Sting (Bite in Beast Form). Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 6 (2d4 + 3) piercing damage, and the target must make a DC 13 Constitution saving throw, taking 8 (2d6) necrotic damage and 8 (2d6) poison damage on a failed save, or half as much damage on a successful one.