Multiattack

Dirge then 1 Bite and 2 Talons or 3 Sorrowful Caws. If it hits Med or smaller creature with two Talons attacks target grappled (escape DC 15). Until this grapple ends harpy can automatically hit target with its Talons and harpy can't make Talons attacks vs. others.

Bite

Melee Weapon Attack: +6 to hit, 5 ft., one target, 8 (2d4+3) piercing damage + 7 (2d6) necrotic. If target is a creature it must make DC 15 Con save or contract harpy's plague disease. If target is disheartened and contracts harpy's plague its hp max is reduced by amount equal to necrotic taken. Until disease is cured target can't regain hp except by magical means and target's hp max decreases by 10 (3d6) every 24 hrs. If target's hp max drops to 0 as a result of this disease target dies.

Talons

Melee Weapon Attack: +6 to hit, 5 ft., one target, 14 (2d10+3) slashing damage.

Sorrowful Caw

Ranged Spell Attack: +6 to hit, 90 ft., one target, 13 (3d6+3) psychic.

Dirge

Telepathically sings a mournful hymn and projects images of sickly and dying loved ones in mind of one creature it can see within 90' of it. Target: DC 15 Wis save or be disheartened for 1 min. While disheartened creature has disadvantage on saves vs. being poisoned or contracting a disease. Disheartened creature can re-save at end of each of its turns success ends effect on itself.