After the Zygon Empire crumbled after their defeat at the hands of the humans the Zygons allied with the Cybermen to defeat the ever growing human empire. The Zygon troops and commanders where converted into cyberform. Cyber Zygons were similar to the Cybermen that originated from humans but had were shorter and faster and most easily recognised by there red head bars. (DW: Cyber) With that their army was defeated and the Cyber-Zygons were extinct.