"From days of long ago, from uncharted regions of the universe, comes a legend. The legend... of Voltron: Defender of the Universe! A mighty robot, loved by good and feared by evil." - Voltron series opening narration
Voltron is a long-standing franchise that began as a cartoon series based on edited and translated footage from the Japanese giant robot anime, Beast King Golion. The series revolves around the ancient guardian of the universe called Voltron, a giant robot composed of five mechanical "space lions" piloted by a team of space explorers from Earth.
The team of space explorers become involved in a war between the planet Arus and the alien empire known as the Drule Supremacy, led by the evil King Zarkon. The explorers are chosen to take the keys that will activate the dormant robot lions and allow them to form Voltron, Arus' only real hope of saving themselves from the Drule onslaught. Throughout the series, Voltron is called into action to battle against the Robeasts: giant cybernetic monsters used by Zarkon to conquer other planets. The Robeasts fulfill the trope of "monster of the week" with a new Robeast being fought in every episode of the show.
An alternate Voltron series exists with a different premise to that of the Lion Force series. This incarnation of Voltron is formed from fifteen different all-terrain vehicles piloted by a multi-species team of space explorers. This team protects the Galaxy Garrison Exploration Fleet as it seeks out habitable planets to support Earth's excess population. The Drule Empire face a similar situation and their fleets clash with the Garrison's constantly in a race to find new worlds to settle.