Trippy Roots

Thorny roots erupt from the ground, forcing each creature in that area to make a dexterity save, or be knocked prone and take 1d6 piercing damage. Any creature that starts its' turn in this area must make the same save. Once concentration is broken, the roots disappear and the terrain becomes normal. This spell can be used once per short/long rest or dream bubble. 

At 5th, 11th and 17th level the damage increases by 1d6.