Pack Tactics. The deinonychus has advantage on an attack roll against a creature if at least one of the deinonychus’ allies is within 5 ft. of the creature and the ally isn't Incapacitated.

Pounce. If the deinonychus moves at least 10 feet straight toward a creature and then hits it with a claw attack on the same turn, that target must succeed on a DC 12 Strength saving throw or take an extra 2 (1d4) Piercing damage and be knocked Prone. If the target is Prone the deinonychus can make one Terrible Claw attack against it as a bonus action.

Multiattack. The deinonychus makes two attacks. One with it's bite and one with it's claws. 

Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., 1 target. Hit: 28 (6d6) Piercing damage. 

Claws. Melee Weapon Attack: +3 to hit, reach 5 ft., 1 target. Hit: 12 (3d6) Slashing damage.

Terrible Claw. Melee Weapon Attack: +3 to hit, reach Special (Target must be Prone and within 5 ft. of the deinonychus)., 1 target. Hit: 19 (4d6) Piercing damage and target it Restrained until a creature knocks the deinonychus off the target with a successful DC 15 STR check. The Restrained target can attempt this but has disadvantage on the STR check.