Stalk. If the coastasaurus moves at least 30 feet straight toward a creature and then hits it with a claw attack on the same turn, that target must succeed on a DC 13 Strength saving throw or be knocked prone. If the target is prone, the coastasaurus can make one bite attack against it as a bonus action.
Amphibious. The coastasaurus can create both in water and on land.
Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 15 (2d10 + 4) piercing damage.
Claw. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) slashing damage. If in water, the player must succeed a DC 15 Strength saving throw or be grappled and dragged underwater.
Description
The coastasaurus is a carnivorous dinosaur of which has developed an evolutionary advantage over other similar carnivores. It has the ability to swim great distances due to its large sac on its back. This acts as a flotation device for the coastasaurus. When in water, the hump on the coastasaurus' back looks like a rock in the water. The coastasaurus is not burdened by the sac on land, as it weighs virtually nothing. It is filled with gasses produced during the digestion process, where it then stores for buoyancy in the water. The coastasaurus is still an apex predator on land.