Armor Class 17 (natural armor)
Hit Points 189 (18d10 + 90)
Speed 30 ft.
Damage Immunities necrotic, poison, psychic, [object Object]
Condition Immunities charmed, exhaustion, frightened, paralyzed, petrified, poisoned
Senses darkvision 60 ft., passive Perception 10
Languages understands all languages but can't speak
Challenge 14
Magic Resistance. The collector has advantage on saving throws against spells and other magical effects.
Unusual Nature. The collector doesn't require air, food, drink, or sleep.
Multiattack. The collector makes two Slam attacks.
Slam. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 18 (3d8 + 5) bludgeoning damage plus 16 (3d10) necrotic damage.
Paralyzing Breath (Recharge 5–6). The collector releases paralyzing gas in a 30-foot cone. Each creature in that area must make a successful DC 18 Constitution saving throw or be paralyzed for 1 minute. A paralyzed creature repeats the saving throw at the end of each of its turns, ending the effect on itself with a success.
Summon Specters (Recharges after a Short or Long Rest). The collector calls up the enslaved spirits of those it has slain; 1d4 specters (without Sunlight Sensitivity) arise in unoccupied spaces within 15 feet of it. The specters act right after the collector on the same initiative count and fight until they're destroyed. They disappear when the collector is destroyed.
Mordenkainen Presents: Monsters of the Multiverse, p. 68