Sam Hill is a human who's been binary-bonded to an Autobot soldier. In tank mode, Sam Hill drives SwitchHammer and they can talk to each other. In robot mode, Sam becomes SwitchHammer's power source and their minds meld into a new personality. Sam is not a Nebulan; he's an Earth astronaut who was trapped in suspended animation for several centuries. His constant confusion and awe at the world of the Transformers is a source of, alternately, amusement or annoyance or inspiration to his fellow adventurers.