Animate Dead Spell
Animate Dead Description: This spell turns the bones or bodies of dead creatures into undead skeletons or zombies that follow your spoken commands.
The undead can follow you, or they can remain in an area and attack any creature (or just a specific kind of creature) entering the place. They remain animated until they are destroyed. (A destroyed skeleton or zombie can't be animated again.)
More: D&D Spells for Animate Dead