Bull Ankylosaurus

Tail. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 18 (4d6 + 4) bludgeoning damage. If the target is a creature, it must succeed on a DC 14 Strength saving throw or be knocked prone.

Hunker Down (1 action). The dinosaur makes an immediate saving throw against any effect currently afflicting it, and has resistance to non-psychic damage until after the next creature's turn.

Tail Sweep (1 action) Melee Weapon Attack: +7 to hit, one or two targets. Hit: 11 (2d6 + 4) bludgeoning damage. If the target is a creature, it must succeed on a DC 14 Strength saving throw or be pushed ten feet.

Trampling Charge (2 actions) moves up to its speed in a straight line, knocking people prone and dealing damage unless they make saves. A target can choose to make a Dexterity Save (DC 14) to be pushed ten feet, avoiding the charge and any damage, or a Strength Save (DC 14) to resist the charge and make an opportunity attack. On a failed save, the target is knocked prone and takes 1d12+4 damage.