Retractable Tusks. The dragon can take an action to protract or retract its tusks.

Flammable Acid. The acid that the dragon launches is highly flammable, often catching fire as soon as it comes into contact with air. When the dragon uses its Acid Breath, roll a d20: on a 5 or higher, the acid catches fire, and any creatures that have come into contact with the acid take 2d6 fire damage. Any objects or structures that have come into contact with the acid take double damage.

Deadly Sting. If the dragon attempts to sting a creature that is already paralyzed by its Sedative Sting, the creature must make a DC 8 Constitution saving throw or the creature drops to 0 HP and starts dying. 

Charge. If the dragon moves at least 10 feet straight toward a target and then hits it with a gore attack on the same turn, the target takes an extra 2d8 bludgeoning damage. If the target is a creature, it must succeed on a DC 15 Strength saving throw or be pushed up to 10 feet away and knocked prone.

Pincer Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 2d6 + 6 piercing damage.

Tusk Gore. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 2d6 + 6 piercing damage.

Sedative Sting. The dragon uses the stinger on the end of its tail and injects a sedative venom into a creature. The targeted creature must succeed a DC 14 Constitution saving throw, and on a fail, the creature becomes paralyzed for 5 rounds. The creature can repeat the saving throw at the beginning of each of its turns, ending the effect on itself with a success. If the creature’s saving throw is successful or the effect ends for it, the creature is immune to the dragon’s Sedative Sting for 24 hours.

Acid Breath (8/Short Rest). The dragon exhales acid in a 60-foot cone. Each creature in that area must make a DC 16 Constitution saving throw, taking 7d6 acid damage on a failed save, or half as much damage on a successful one.