Charnel Whisperer

Spellcasting (Pact Magic). The whisperer is an 8th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 14, +6 to hit with spell attacks). It knows the following spells:
Cantrips (at will): chill touch, eldritch blast, mage hand
1st–4th level (2 4th-level slots): animate dead, blight,
comprehend languages, detect magic, dispel magic, fear, hold person, mirror image, unseen servant

Psychic Feast. The lurker can feed for 1 minute on a humanoid or monstrosity corpse with flesh at least 24 hours dead to absorb some of the lingering traces of memory and knowledge that the creature possessed in life. This adds a +1 bonus on a skill of the lurker’s choice that the creature was proficient in. The lurker gains only one bonus from any given corpse. At the GM’s discretion, a particularly ancient corpse might grant a larger bonus or a bonus to more than one skill. The lurker can maintain three separate bonuses. If it uses this trait when it already has the maximum number of bonuses, it must forget one of the current bonuses in order to replace it with one from the new corpse.

Grave Nose. The Lurker has advantage on Wisdom (Perception) checks that rely on smell to notice or recognize corpses, decaying things, meat, and undead creatures.

Inured to Disease. The lurker is immune to nonmagical diseases and has advantage on saving throws against magical diseases.

Scrounger. The lurker has advantage on Wisdom (Perception) and Intelligence (Investigation) checks to find objects in rubble or undergrowth, buried, or otherwise hidden from view.

Multiattack. The charnel whisperer casts a cantrip it knows and
makes two attacks: one with its bite and one with its claws.

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 9 (1d4 + 2) piercing damage and (4d6 ) psychic damage. The charnel whisperer regains hitpoints equal to the psychic damage dealt.

Claws. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (2d4 + 2) slashing damage.

Call of the Grave (1/Day). If the whisperer fails an Intelligence, Wisdom, or Charisma saving throw, it can use its reaction to roll again. It uses the new result in place of its original result, which can make it succeed on the saving throw after all.