aboling lair in subterranean lakes or the rocky depths of the ocean, often surrounded by the ruins of an ancient, fallen aboleth city. An aboleth spends most of its existence underwater, surfacing occasionally to treat with visitors or deranged worshipers.

Lair Actions

When fighting inside its lair, an aboling can invoke the ambient magic to take lair actions. On initiative count 20 (losing initiative ties), the aboling takes a lair action to cause one of the following effects:

• Pools of water within 90 feet of the aboling surge outward in a grasping tide. Any creature on the ground within 20 feet of such a pool must succeed on a DC 12 Strength saving throw or be pulled up to 20 feet into the water and knocked prone. The aboling can’t use this lair action again until it has used a different one.
• Water in the aboling’s lair magically becomes a conduit for the creature’s rage. The aboling can target any number of creatures it can see in such water within 90 feet of it. A target must succeed on a DC 14 Wisdom saving throw or take 7 (2d6) psychic damage. The aboling can’t use this lair action again until it has used a different one.

Regional Effects

The region containing an aboling’s lair is warped by the creature’s presence, which creates one or more of the following effects:

• Underground surfaces within 1 mile of the aboleth’s lair are slimy and wet and are difficult terrain.

If the aboling dies, the effect fades over the course of 3d10 days.