Multiattack. The tyrannosaurus makes two attacks: one with its bite and one with its tail, and uses it's Battle Roar. It can't make both attacks against the same target.

Bite. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 24 (3d12 + 5) piercing damage. If the target is a Medium or smaller creature, it is grappled (escape DC 15). Until this grapple ends, the target is restrained, and the yutyrannosaurus can't bite another target.

Tail. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 20 (3d8 + 7) bludgeoning damage.

Terrorizing Roar (recharge 5-6). The Yutyrannus unleashes a terrorizing scream. Each creature within a 50ft cone must succeed on a DC15 Wisdom saving throw or be frightened for one minute. if frightened by the roar the creature must take the Dash action and move away from you by the safest available route on each of its turns, unless there is nowhere to move. a creature can repeat the saving throw at the end of its turn, ending the effect on a success.

Battle Roar. The Yutyrannus unleashes an empowering roar, granting all allied creatures within 50ft the effects of a bless spell until the start of the Yutyrannus' next turn.