Black Philip

Charge. If Black Phillip moves at least 10 feet straight toward a target and then hits it with a Ram attack on the same turn, the target takes an extra 2d8 thunder damage. All creature within a 10ft cube of the attack suffer the effects of Thunderwave. (A wave of thunderous force sweeps out from you. Each creature in a 15-foot cube originating from you must make a Constitution saving throw. On a failed save, a creature takes 2d8 thunder damage and is pushed 10 feet away from you. On a successful save, the creature takes half as much damage and isn't pushed.

In addition, unsecured objects that are completely within the area of effect are automatically pushed 10 feet away from you by the spell's effect, and the spell emits a thunderous boom audible out to 300 feet.)

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

Earthquake. When Black Phillip is reduced to 1/3 of total HP (25) his movement causes 1d6 thunder damage, he gets his thunder step ability recharged, and he emits a Thunderwave in a 15 foot radius from himself. . 

Ram. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. 2d8+5  bludgeoning damage.

Thunder Step. (Recharge 5-6) You teleport yourself to an unoccupied space you can see within range. Immediately after you disappear, a thunderous boom sounds, and each creature within 10 feet of the space you left must make a Constitution saving throw DC 14, taking 3d10 thunder damage on a failed save, or half as much damage on a successful one. The thunder can be heard from up to 300 feet away.

Movement: Black Phillip can use his reaction to move 15ft  without provoking an opportunity attack.