Calopus

Keen Hearing and Smell. The calopus has advantage on Wisdom (Perception) checks that rely on hearing or smell.

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

Charge. If the calopus moves at least 20 feet straight toward a target and then hits it with a ram attack on the same turn, the target takes an extra 5 (2d4) bludgeoning damage. If the target is a creature, it must succeed on a DC 13 Strength saving throw or be knocked prone.

Sure-Footed. The ram has advantage on Strength and Dexterity saving throws against effects that would knock it prone.

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 10 (2d6 + 3) piercing damage. If the target is a creature, it must succeed on a DC 13 Strength saving throw or be knocked prone.

Ram. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 8 (2d4 + 3) bludgeoning damage plus 3 (1d6) force damage.