Aboleth

Regional Effects

Source: Monster Manual (2024)

The region containing an aboleth’s lair is warped by it, creating the following effects:

• Foul Water. Water sources within 1 mile of the lair are supernaturally fouled. Creatures other than the aboleth and its allies that drink such water must succeed on a DC 15 Constitution saving throw or have the Poisoned condition for 1 hour.
• Psionic Projection. While in its lair, the aboleth can cast Project Image, requiring no spell components and using Intelligence as the spellcasting ability (spell save DC 16). When casting the spell this way, the spell’s range is 1 mile, and the aboleth can use its telepathy as if it were in the illusion’s space.

If the aboleth dies or moves its lair elsewhere, these effects end immediately.