Multiattack

The spree demon makes two claw attacks. If both attacks hit the same target, the target must succeed on a DC 14 Wisdom saving throw or become frightened for 1 minute. While frightened this way, the creature believes it has shrunk to half its normal size. All attacks against the creature do an extra 7 (2d6) psychic damage, and the creature's attacks do half damage. A frightened creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Claw

Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) slashing damage plus 10 (3d6) poison damage, and the creature must make a DC 14 Constitution saving throw. On a failure, the target can't take reactions and must roll a d10 at the start of each of its turns to determine its behavior for that turn for 1 minute. This works like the confusion spell. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to this effect for the next 24 hours.