databank
900 year diary
tractators
A large isopodan species, forced to wander through space, burrowing their way through planets. They were guided by the Gravis, without whose influence, the Tractators were simply mindless drones. Tractators had visited Trion at some point in the past. The Doctor discovered them on Frontios, where the Gravis had used the Tractators' gravity controlling powers to draw down a colony ship. The Gravis was using pieces of dead colonists to power his tunnelling machines. The Doctor removed the Gravis to the planet Kokolkron, leaving the remaining Tractators harmless and aimless.