Multiattack

The spinosaurus makes one Bite attack and two Claw attacks.

Bite

Melee Weapon Attack: +12 to hit, reach 15 ft., one target. Hit: 33 (4d12 + 7) piercing damage. If the target is a Large or smaller creature, it is grappled (escape DC 18). Until this grapple ends, the target is restrained, and the spinosaurus can't Bite another target.

Claw

Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 21 (4d6 + 7) slashing damage.

Tail

Melee Weapon Attack: +12 to hit, reach 20 ft., one target. Hit: 16 (2d8 + 7) 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 creature can repeat 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's Frightful Presence for the next 24 hours.