Gengar (5e Creature)
From D&D Wiki
Medium undead, any alignment
Damage Immunities poison
Cursed Body. A creature that hits the gengar with a melee attack while within 5 feet of it must succeed on a DC 16 Wisdom saving throw or be frightened of the gengar for 1 minute. A creature can repeat this saving throw at the start of each of its turns, ending the effect on a success.
Shadow Tag. When the gengar hits a creature with an opportunity attack, the creature must succeed on a DC 16 Wisdom saving throw or its speed becomes 0 for the rest of the turn.
Multiattack. The gengar makes two attacks, either with its night shade or with its shadow ball.
Night Shade. Melee Spell Attack: +8 to hit, reach 5 ft., one target. Hit: 20 necrotic damage.
Shadow Ball. Ranged Spell Attack: +8 to hit, range 20/60 ft., one target. Hit: 19 (4d6 + 5) psychic damage.