Bert, the Armoured Siege Elephant

Heavily Armoured. Bert wears Enspelled Plate Barding (Level 3), imbued with 6 charges of the spell Aura of Vitality.

Frost Bite. If Bert moves at least 20 feet straight toward a creature and then hits it with a gore attack on the same turn, the target takes an extra 19 (3d12) Cold damage.

Flyby. Bert doesn't provoke opportunity attacks when it flies out of an enemy's reach.

Keen Hearing and Smell. Bert has advantage on Wisdom (Perception) checks that rely on hearing or smell.

Siege Monster. Bert deals double damage to objects and structures.

Gore. Melee Attack Roll: +7, reach 5 ft. Hit: 18 (2d12 + 5) Piercing damage.

Aura of Vitality (6 charges, restore 1d6 charges daily at dawn). (Concentration, 1 minute) Bert casts Aura of Vitality from his Enspelled Plate Barding, creating an aura that radiates in a 30-foot Emanation for the duration. Upon creating the aura and at the start of each of Bert's turns, Bert can restore 7 (2d6) Hit Points to one creature within it.