Professor Markus Strath needed a lab assistant capable of directly handling hazardous materials - so he decided to build one, in the form of a humanoid robot. During the construction, Professor Strath's wife spilled a sugar-free soft drink on the robot's responometer, which caused an electrical short followed by a power surge in the robot's experimental sub-centrifugal paraphentomaxillary energy core, which in turn produced a reverse mnemonic-impedance/phase-preponderance cascade in the robot's CPU. As a result, the robot gained self-awareness and an occasionally annoying degree of autonomy, and furthermore took to calling itself ZEP (Zoetic Electronic Person).
Zep fulfills his primary function as Professor Strath's lab assistant, but in his free time he fights crime on the streets of Paragon City.