- Oxygen- He was a walking Oxygen tank.
- Helium- He was a rubber robot able to expand like a balloon.
- Chloroform- He was a cylinder shaped robot with holes that could emitt chloroform.
- Carbon Monoxide- He was basically a walking lit Bunsen Burner.
- Carbon Dioxide- Oddly enough, he looked like an anthropomorphic (giving human traits to non-human things) dry ice crystal.
Unlike the Metal Men (who were the Doc's size), the Gas Gang's size varied from 1/3 to twice Doc's size. He ordered the Gas Gang to attack the Metal Men. Chloroform used it's nitrous oxide to cause the Metal Men to have hysteria fits (causing Mercury to literally break up laughing). But Lead turned into a wall to block it. Oxygen tried to rust them. During a chase, Carbon Monoxide tried to poison them. Carbon Dioxide tried to freeze them. Gold manage to turn into a cage and trap the Gas Gang. He connected himself to high voltage conductors causing the Gas Gang to melt and turn into steam. Somehow the steam turned Doc back to normal.