The Ace Security Guard is a part of T.O. Morrow's mutated forces at Ace Chemicals. Originally intended to be used to reinforce the Joker's Streetgang as part of the newly designed Joker Toxin experiments, the forces now work solely for T.O. Morrow to defend him from the villain's retribution.
- The uniforms Ace Security Guards wear are the same as the Metropolis Police Department.