Andrewtherium

Rending Charge. If the andrewtherium moves at least 20 feet straight toward a target and then hits it with a slam or bite attack on the same turn, the target takes an extra 9 (2d8) damage. If the target is a creature, it must succeed on a DC 15 Constitution saving throw or have its hit point maximum decreased by the amount of extra damage dealt.

Multiattack. The andrewtherium makes two melee attacks. If both attacks hit, the andrewtherium gains advantage on its next saving throw against a condition afflicting it.

Head Slam. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 5) bludgeoning damage.

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 12 (2d6 + 5) piercing damage. If the target is a creature, it must succeed on a DC 14 Strength saving throw or be knocked prone.

Stomp. Melee Weapon Attack: +8 to hit, reach 5 ft., one prone target. Hit: 9 (1d10 + 5) bludgeoning damage.