Necrobinding Serum

This potent alchemical serum is distilled from the body of an intelligent corporeal undead who seeks to establish absolute control over his undead minions. In a wicked ritual, the creator sloughs his own flesh into specially prepared receptacles filled with mystic herbs, where it dissolves and ferments in fluids siphoned from his body. When completed, the creator can then inject the fluids into an undead creature, allowing him to control it for 7 days if under the effect of a command undead spell.