Multiattack

The dissimortuum makes three claw attacks.

Claw

Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 15 (3d8 + 2) slashing damage.

Terrifying Mask

Each non-undead creature within 60 feet of the dissimortuum that can see it must make a successful DC 15 Wisdom saving throw or be frightened for 1d8 rounds. If a target's saving throw is successful or the effect ends for it, the target becomes immune to all dissimortuum's terrifying masks for the next 24 hours.