Spinosaurus

Tamed. The spinosaurus will never willingly attack any reptilian humanoid, and if forced or magically compelled to do so, it suffers disadvantage on attack rolls. Up to twelve Medium or four Large creatures can ride the spinosaurus. This trait disappears if the spinosaurus spends a month away from any reptilian humanoid.

Siege Monster. The spinosaurus deals double damage to objects and structures.

Multiattack. The spinosaurus makes one bite attack and two claw attacks.

Bite. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 34 (4d12 + 8) piercing damage. If the target is a Large or smaller creature, it is grappled (escape DC 18). When the spinosaurus moves, the grappled creature moves with it. Until this grapple ends, the target is restrained and the spinosaurus can't bite another target.

Claw. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 22 (4d6 + 8) slashing damage.

Tail. Melee Weapon Attack: +13 to hit, reach 20 ft., one target. Hit: 21 (3d8 + 8) bludgeoning damage.

Frightful Presence. Each creature of the spinosaurus' choice that is within 120 feet of the spinosaurus and aware of it must succeed on a DC 18 Wisdom saving throw or become frightened for 1 minute. A frightened creature repeats the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the spinosaurus' Frightful Presence for the next 24 hours.

Move. The spinosaurus moves up to half its speed.

Roar. The spinosaurus uses Frightful Presence.

Tail Attack (Costs 2 Actions). The spinosaurus makes one tail attack.