Giant Sea Horse

If the giant sea horse 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 7 (2d6) damage.
If the target is a creature, it must succeed on a DC 11 Strength saving throw or be knocked prone.

The giant sea horse can breathe only underwater.

Melee Weapon Attack: +4 to hit, reach 5 ft.. Hit: 5 (1d6 + 2) bludgeoning damage.