Dead Thrall

You touch the corpse of a dead creature whose level or challenge rating is less than yours. The creature is now alive and under your control. Any conditions or damage to the creature are healed. The creature's type is Undead, and it is under your control for the duration. The creature rolls its own initiative in combat. Once the spell ends, the creature continues to be alive, but is no longer under your control. Your control over the creature ends if it is targeted by dispel magic, remove curse, or greater restoration.

At Higher Levels. When you cast this spell using a spell slot above 5th, you increase the duration that the creature is under your control. The duration increases to 24 hours at 6th level, 1 month at 7th level, and 1 year at 8th level. At 9th level, the control lasts until the magic is dispelled.