They appear like reddish-greenish skinned humans with an extra eye at the center of their forehead, and a robotic arm and a robotic leg. But they walk rather like a normal human.
The Pyrobots have a unique history, and Venus was able to develop life and civilization at a much shorter time frame than the Earth. An evil race, the Star Zombies, tried to invade Venus, but the Pyrobots teamed up with the human race to kill off the Star Zombies. The Pyrobots look forward to peaceful relations with humans.