The Nevermore is a spellcaster. Its spellcasting ability is Constitution (save DC 15, +7 to hit with spell attacks). It has the following spells prepared.
Cursed Touch: Whenever the Nevermore deals damage to a creature (or directly touches its skin) it infects it with the Nevermore curse. The more damage the Nevermore does the more infected the creature is, however it is up to the DM exactly how much and how fast it will spread.
Dripping Curse: If you are within 5ft of the Nevermore, each turn you must succeed on a DC 10 Dexterity Saving throw to avoid getting touch by the Nevermores "fog". If you fail you become cursed as per Cursed Touch.
Multiattack: The Nevermore makes 3 attacks with its Claws.
Claws. Melee Weapon Attack +7
Hit: 15 (3d8+3) Slashing damage, and 10 (1d10+5) Necrotic damage
Humanoid Nevermores are usually found in and around settlements.