Multiattack. The tyrannosaurus makes one Bite attack and one Tail attack.

Bite. m +10, reach 10 ft. Hit: 33 (4d12 + 7) Piercing damage. If the target is a Large or smaller creature, it has the Grappled condition (escape DC 17). While Grappled, the target has the Restrained condition and can't be targeted by the tyrannosaurus's Tail.

Tail. m +10, reach 15 ft. Hit: 25 (4d8 + 7) Bludgeoning damage. If the target is a Huge or smaller creature, it has the Prone condition.