Crysalis

A 10-foot radius area on the ground you choose within range is surrounded by a cluster of sharpened crystals. All creatures within range must make Dexterity saving throws, taking 1-8d12 cold damage on a failed save, or half as much on a successful one.

You roll a d8 to determine how many d12’s are used to roll this spell’s cold damage. For example, rolling a 4 causes the spell to deal 4d12 damage. The crystals also rise 10 feet upward for each d12.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d12 for each slot level above 4th, meaning the crystals also rise 10 feet higher each level. These d12s are independent of the d8 roll.