Alien Invaders: Rockhead, the Living Mountain by Max Silver (author) (UK edition)

Five awsome aliens have been unleashed from the darkest corner of the galaxy – and they’re out to destroy the universe.

Only Cosmo, a young boy from planet Earth, has the power to stop them. Recruited by the elite defence organisation G-Watch to defend the galaxy, Cosmo must prove himself and comence battle against the deadliest aliens in space…

The first title in this action-packed series sees Cosmo discover the truth about his fathers mysterious past, and take up his role as a defender of the galaxy. When the mighty alien Rockhead is sent to destroy G-Watch headquarters, only Cosmo has the power to stop him. But will the young Earthling be able to defeat the monstrous mountain alien?