Ashstag

Charge. If the ashstag moves at least 20 feet straight toward a target and then hits it with a gore attack on the same turn, the target takes an extra 7 (3d6) damage. If the target is a creature, it must succeed on a DC 13 Strength saving throw or be knocked prone.

Shadow Stalk. The ashstag may teleport up to 20 ft. as a free action before it takes a movement action.

Gore. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 8 (1d10 + 3) piercing damage.

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one prone creature. Hit: 12 (2d8 + 3) piercing damage.

Teleport. If the ashstag is hit by an attack, it makes a DC 16 wisdom saving throw. On a sucess, the ashstag instead takes no damage and may teleport up to 20 ft.