Asht's Grotesque Transformation

You attempt to alter the physical form of a creature you can see within range, transforming them into a manifestation of twisted flesh and bone. Constructs, incorporeal undead, and creatures that lack flesh and bones are immune to this spell. The target must make a Constitution saving throw, or become transformed into a fleshy abomination and its speed is halved for the duration. At the end of each of its turns, the target must succeed on a Constitution saving throw or take 4d10 necrotic damage as its form continues to twist and pull, causing severe pain. On a successful save, the spell ends.

At Higher Levels: When you cast this spell using a spell slot of 5 level or higher, the damage increases by 1d10 for each slot level above 4 level.