Dominator

The Dominators were a race of humanoids who controlled much of the Ten Galaxies. They were intensely utilitarian, and hesitant to misuse any amount of energy for matters that did not directly benefit them and their mission. This was especially the case in energy management of their robotic laborers, Quarks.

Biology
The Dominators were similar to humans in form, but over two and half metres tall with pale skin, dark hair and red-rimmed green eyes. (PROSE: The Dominators)

Technology
The Dominators used saucer-shaped craft which were powered by negative mass flux absorption. This negative mass flux absorption allowed the ships to absorb radiation and convert it to propulsion.

The Dominators used the Quarks as labourers in their forces. Though they used them for a variety of tasks, they preferred to use slaves where they could, in order to reserve their energy.

The Dominators used Neuro-Initiative Tests, or NIT. These tests were intelligence tests where the subject was shocked and then had to fit objects into similarly shaped holes. These tests were used to find out the suitability of other species for slavery and to determine their level of threat. (PROSE: The Dominators)

History
The Dominators controlled much of the Ten Galaxies, which they took by ruthless, calculated force. Eventually, their Quark forces were stretched thin, which meant they required slaves in order to fill the jobs that the Quarks were taken from. Several planets were researched for this purpose, such as Epsilon Zero Gamma and Dulkis.

The scouts sent to Dulkis consisted of Toba and Rago. The plan was to take the strongest Dulcians as slaves and then use a special seeding device dropped into the magma of the planet in order to destroy it. This destroyed planet would then have its energy used for powering the Dominator fleet. Though the Dulcians were unwilling to fight back, the Second Doctor was able to stop them from destroying the planet. (TV: The Dominators)

In 1984, the Dominators and the Quarks attempted to acquire Earth's core as a fuel source, but this was foiled by UNIT. (COMIC: The Fires Down Below)