Traits

Amphibious.

The Abyssal Remnant can breathe both air and water.

Abyssal Maw.

Creatures grappled by the Abyssal Remnant automatically fail concentration checks.

Reality Warping Presence.

At the start of each of its turns, creatures within 30 feet of the Abyssal Remnant must make a DC 17 Wisdom saving throw or experience warped reality (GM’s choice):

• Their vision distorts, seeing false enemies (disadvantage on Perception checks).
• They lose a sense of depth, suffering a -2 penalty to attack rolls.
• They hear voices whispering truths and lies, causing disadvantage on Intelligence checks.
• If they roll a natural 1 on any saving throw or attack while affected, they take 4d6 psychic damage.

Eldritch Depths.

While in water, the Abyssal Remnant can teleport up to 60 feet as a bonus action, leaving behind a swirling void that obscures vision in a 10-ft radius for 1 round.

Actions

Multiattack.

The Abyssal Remnant makes two Tentacle attacks and may use Mind Drown if available.

Tentacle. Melee Weapon Attack: +11 to hit, reach 15 ft., one target.

Hit: 20 (3d8 + 6) bludgeoning damage. The target must succeed on a DC 19 Strength saving throw or be grappled. A creature grappled by two tentacles is also restrained.

Mind Drown (Recharge 5–6).

The Abyssal Remnant releases a pulse of dark energy in a 30-foot radius. All creatures in range must make a DC 18 Intelligence saving throw or take 6d10 psychic damage and be stunned until the end of their next turn. On a success, they take half damage and aren’t stunned.

Abyssal Maw.

The Abyssal Remnant can attempt to swallow a grappled, restrained, or incapacitated creature of Large or smaller size. The target must make a DC 18 Dexterity saving throw or be swallowed. While swallowed, the target is blinded and restrained, takes 28 (8d6) acid damage at the start of each of the Abyssal Remnant’s turns, and has total cover from attacks outside the creature. If the Remnant takes 40 or more damage in one turn, it must make a DC 20 Constitution saving throw or regurgitate all swallowed creatures.

Legendary Actions (Optional if you want a bigger fight!)

The Abyssal Remnant can take three legendary actions, using one at a time at the end of another creature’s turn.

• Lurking Dread. The Abyssal Remnant teleports 30 feet in water, leaving a cloud of inky darkness.
• Tentacle Slam (Costs 2 Actions). It makes a Tentacle attack against each creature it has grappled.
• Psychic Undertow (Costs 3 Actions). It forces all creatures within 30 feet to make a DC 17 Wisdom saving throw or be pulled 20 feet closer and take 3d8 psychic damage.