Betrayal of Flesh

You send a stream of dark energy into one creature within range making their flesh ripple and convulse, the target must make a constitution saving throw, taking 5d8 necrotic damage on a failed save or half as much damage on a successful one as their flesh tears itself from their body. The pile of their flesh animates at the beginning of your next turn and remains for the duration of the spell, use the statistics of a zombie with a number of hit points equal to the necrotic damage dealt and a bonus to attack and damage rolls equal to your spell casting ability modifier. It follows your spoken commands and acts immediately after your turn. Every time the undead damages the creature targeted by this spell it regains a number of hit points equal to half the damage dealt as it tears off a chunk of their flesh and adds it to its own mass. 

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d8 for each slot level above 4th.