Tyrannosaurus Rex

Hardy. Any critical hit against the dinosaur becomes a normal hit.

Multiattack. The tyrannosaurus makes one Bite attack and one Tail attack. It can't make both attacks against the same target.

Bite. _Melee Weapon Attack:_ +8 to hit, reach 10 ft., one creature. _Hit:_ 31 (4d12+5) piercing damage. If the target is a Large or smaller creature, it is grappled (escape DC 16). Until this grapple ends, the target is restrained, and the tyrannosaurus can't Bite another target.

Tail. _Melee Weapon Attack:_ +8 to hit, reach 10 ft., one creature. _Hit:_ 23 (4d8+5) bludgeoning damage.

Rending Shake. While grappling a creature, the tyrannosaurus shakes its head, tearing at the creature. The grappled creature must succeed on a DC 16 STR save or take 6 (1d12) slashing damage and be thrown up to 20 feet in a random direction and knocked prone. If the thrown target strikes a solid surface, the target takes 3 (1d6) bludgeoning damage for every 10 feet it was thrown. If the target is thrown at another creature, that creature must succeed on a DC 16 DEX save or take the same damage and be knocked prone.