Beast Within

You target a humanoid, giant, or aberration of CR 5 or less who is Large or smaller within range. That creature must succeed on a Constitution or Wisdom saving throw (your choice) or be reduced to 0 hit points, have its body destroyed as if being torn apart, and have ancient magic burst from the body and transform into an unaligned Beast or Monstrosity of the target's CR or lower of your choice on a failure, or have disadvantage on all saving throws for the next hour on a success.