My Zombie BodyguardSelf-Defense Key Chain, Color: PURPLE-GREEN ACCENTS. My Zombie Bodyguard (MZB) brand self-defense key chains are constructed from rugged cold-rolled steel plate. MZBs are a highly effective and unique self-defense tool, which can be used by women and men in environments where handguns, stun guns or other self-defense tools are inconvenient or prohibited. MZBs are a unique conversation piece and come in a variety of colors and coatings.