Terror Bird

Pack Tactics. The terror bird has advantage on attack rolls against a creature if at least one of the bird's allies is within 5 feet of the creature and the ally isn't incapacitated.

Passing Bite. Terror birds who move at least 20 feet straight toward a target have advantage on the next attack roll against that target.

Serrated Beak. Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 14 (3d6 + 4) slashing damage. The target must succeed on a DC 12 Constitution saving throw or take 7 (2d6) slashing damage at the beginning of its next turn.