Armor Class 14 (natural armor)
Hit Points 93 (11d8 + 44)
Speed 30 ft., swim 30 ft.
Skills Perception +4
Damage Resistances psychic
Condition Immunities charmed, frightened
Senses darkvision 120 ft., passive Perception 14
Languages Common, Deep Speech, telepathy 60 ft.
Challenge 5
Abolethic Vessel. The spawn must obey its aboleth master.
Amphibious. The spawn can breathe air and water.
Water Dependency. The spawn takes 6 (1d12) acid damage every 10 minutes it goes without being immersed in water.
Multiattack. The spawn makes one Spear attack, two Tentacle attacks, and one Psychic Lash attack.
Spear. Melee or Ranged Weapon Attack: +7 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 7 (1d6 + 4) piercing damage, or 8 (1d8 + 4) piercing damage when used with two hands to make a melee attack.
Tentacle. Melee Weapon Attack: +7 to hit, reach 10 ft., one creature. Hit: The target is grappled (escape DC 14) and takes 9 (2d8) psychic damage at the start of each of its turns until the grapple ends. The spawn has four tentacles, each of which can grapple one creature.
Psychic Lash. Ranged Spell Attack: +7 to hit, range 120 ft., one creature. Hit: 18 (4d8) psychic damage.
CRCotN, p. 135