The yowler lets loose a horrid scream. Each hostile creature within 30 feet of the yowler that can hear it must succeed on a DC 12 Wisdom saving throw or become frightened for 1 minute. A creature 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 the yowler's Yowl for the next 24 hours.