Bio: While all four "Free-Fall Warriors" are named, it is Machine-Head who gets the most panels in the Doctor Who comic strip of the same name. This is because he personally pilots the two lead characters, the Fourth Doctor and Ivan Asimoff, during the Festival of the Five Planets. His ship, along with his passengers, end up crashing on an asteroid.
His name is more than just a nickname. As can be seen from the picture at right, he's literally got a spaceship for a head.