Lava Spread. The size of the volcano increases by 5 feet diameter on each of it's turn unless it takes cold, thunder, or water damage.

Illumination. The volcano sheds bright light in a 30-foot radius and dim light in an additional 30 feet.

Water Susceptibility. For every 5 feet the elemental moves in water, or for every gallon of water splashed on it, it takes 1 cold damage.

Fireball. Ranged Spell. +5 to hit, range 150ft, 20ft radius. Hit:  (6d6) fire damage, half damage on a dexterity saving throw. Any object not warn or carried is ignited.

Fire Touch. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 10 (2d6 + 3) fire damage. If the target is a creature or a flammable object, it ignites. Until a creature takes an action to douse the fire, the target takes 5 (1d10) fire damage at the start of each of its turns.