Baryonyx

Baryonyx would live in the swamps of dinosaur plains this meat eater was 5 blocks above the player but this water beast would act similar to polar bears if you hurt their young they will fight you and if you retreat from the battle they will stalk you forever to avoid this from happening you have to kill it but that will be hard even though it may have the same amount of hp as the player its powerful bite will deal 10 damage and the same with claws so to kill it you would want to use a bow & arrow or crossbow to tame one would be tricky you have to explore the ocean and find a baryonyx kingdom then once you reach the egg all you have to do is mine it and a baby pops out then it will follow you around once grown up you can ride it with a saddle.