Keen Sight. The goose has advantage on Wisdom (Perception) checks that rely on sight.   Swarm. The swarm can occupy another creature's space and vice versa, and the swarm can move through any opening large enough for a Small Goose. The swarm can't regain hit points or gain temporary hit points.   Frightful Presence. Each creature of the goose's choice that is within 30 ft. of it and aware of it's presence must succeed on a DC 14 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 goose's Frightful Presence for the next 24 hours.   If the swarm has less than half its hit points, the DC is 12.