- "They live in the ground below, pulling us to them in our times of weakness..."
- ―Vislor Turlough
Tractators (Phenomenoptera sp.) are a sapient species of man-sized crustaceanoids, shaped like a bipedal pill bug with fish-like facial features and a pair of antennae. Tractator colonies consist of a hive mind in which only one individual is truly sapient, and referred to as the Gravis. The remaining drones are little more than mindless beasts, mentally controlled by their leader.
They are most (in)famous by their psychic abilities which allow them certain control over gravity: when the Tractators locate a surface dweller which is weak and/or dying, they manage to telekinetically drag the victim into the ground to the domain of the Tractators. Once there, the victims become part of their bio-cybernetic machinery, which uses humanoid minds as a source of energy. In ideal conditions, their gyrokinetic powers can be strong enough to pull spaceships and asteroids towards a planet, and even to disintegrate a TARDIS. Planets known to have been invaded by the Tractators include Trion and Frontios. They are also familiar with the Time Lords, at least the one known as the Doctor.
- Doctor Who, season 21 (Fifth Doctor) - Frontios (1984)