Amphibious.

The kuo-toa can breathe air and water.

Otherworldly Perception.

The kuo-toa can sense the presence of any creature within 30 feet of it that is invisible or on the Ethereal Plane. It can pinpoint such a creature that is moving.

Slippery.

The kuo-toa has advantage on ability checks and saving throws made to escape a grapple.

Spellcasting.

The kuo-toa is a 10th-level spellcaster. Its spellcasting ability is Wisdom (spell save DC 14, +6 to hit with spell attacks). The kuo-toa has the following cleric spells prepared:

Cantrips (at will): guidance, sacred flame, thaumaturgy
1st level (4 slots): detect magic, sanctuary, shield of faith
2nd level (3 slots): hold person, spiritual weapon
3rd level (3 slots): spirit guardians, tongues
4th level (3 slots): control water, divination
5th level (2 slots): mass cure wounds, scrying

Sunlight Sensitivity.

While in sunlight, the kuo-toa has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.

Actions

Multiattack.

The kuo-toa makes two melee attacks.

Scepter.

Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) bludgeoning damage plus 14 (4d6) lightning damage.

Unarmed Strike.

Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 5 (1d4 + 3) bludgeoning damage.

Environment: Underdark

Kuo-toa Archpriest