Disguise Undead

You cover a willing undead creature with an illusion of flesh, hair, and clothes, giving them the look of a regular humanoid. The spell can't change the target's size more than an inch in any direction, but you choose the race and general appearance on casting the spell.

While concentrating on the spell, you can speak through the mouth of the target. The spell doesn't change your voice however, so a creature that hears both you and the undead speak may get suspicious.

To discern that the undead are disguised, a creature must take the Study action to inspect the undead's appearance and succeed on an Intelligence (Investigation) check against your spell save DC. A creature who touches the undead or hears both it and you speak in the span of 30 seconds gets advantage on the roll.

At higher levels. When you cast this spell using a spell slot of 3rd level or higher, you can target an additional undead creature for each slot level above 2nd.