Surtsey

You cause a serpentine lava dragon to rise, diving freely through the ground and able to surface many feet away. This dragon dives and emerges at a point within range of the spell that you can see; creatures in a 20-foot area of the diving or emerging point must make a Dexterity saving throw. On a failure, an affected creature takes 8d6 incinerating damage and chunks of molten rock solidify onto its body. You can use your bonus action to make the dragon emerge from one point and dive into another within range of the spell at a point you can see.

A creature that has chunks of solidified rock on its body must use its action and make a Medicine check to successfully remove them. If it tries to shake off the chunks of rock quickly without making this check, the creature takes 7d6 incinerating damage. While creatures have chunks of rock stuck to their bodies, they lose half their movement speed and have disadvantage on attack rolls and Dexterity saving throws.

At Higher Levels. When you cast this spell by spending Mana points equal to a 9th-level spell or higher, the incinerating damage increases by 2d6.