Animate Skulls

This spell creates an undead servant. Choose a pile of bones or a corpse of a Medium or Small humanoid within range. Your spell imbues the target with a foul mimicry of life, raising it as an undead creature, the creatures skull burns with a magical aura that and burns away any remaining flesh separating itself from the hosts body if it has one and begins hovering. The target's head becomes an animated skull 

On each of your turns, you can use a bonus action to mentally command any creature you made with this spell if the creature is within 60 feet of you (if you control multiple creatures, you can command any or all of them at the same time, issuing the same command to each one). You decide what action the creature will take and where it will move during its next turn, or you can issue a general command, such as to guard a particular chamber or corridor. If you issue no commands, the creature only defends itself against hostile creatures. Once given an order, the creature continues to follow it until its task is complete.

The creatures are under your control for 8 hours, after which the magic animating the skulls fade and the skulls fall to the ground and crumble to dust if you recast the spell you can refresh the timer back to 8 hours and the skulls will remain for the new duration. 

At Higher Levels. When you cast this spell using a spell slot of 4th or higher you can animate an additional skull per level. Each of the creatures must come from a different corpse or pile of bones.