Vardan

The Vardans were a telepathic race with the ability to mentally travel along any broadcast wavelength.

Physical characteristics
Having a default, near-Human form, the Vardans could also change into a shimmering energy form. While on the planet of Gallifrey during their invasion of that world, they appeared in helmets and green uniforms. Their telepathy had limits, as far as lead acting as a shield to their telepathic powers, a disability the Doctor would use this weakness to his advantage. (DW: The Invasion of Time) They can "broadcast" themselves, travel from place to place at will (DW: The Invasion of Time, NA: No Future) and travel down telephone lines. (NA: Return of the Living Dad) Despite this, they used spacecraft. (DW: The Invasion of Time)


 * We do not know whether or not they can travel only at the speed of light.

History
The Vardans were militaristic species who lived by the principle of "survival of the very fittest", though some had a more sympathetic attitude. (NA: No Future)


 * Based on the non-appearance of female Vardans, it seemed they had only a marginal place in Vardan society.

They evolved from a near-human form and developed their powers of telepathy as a weapon and perfected them to the point where they could, at will, change into forms of electromagnetic energy. (NA: No Future)

The Vardans contacted the Doctor during his fourth incarnation to ask him to assist them in taking over Gallifrey, the home planet of the Time Lords. The Doctor nominated himself, and was made, Lord President, before placing Varda in a time loop. At the same time, Gallifrey was invaded by Sontarans, who had used the Vardans so that the Sontarans, themselves, could invade Gallifrey. (DW: The Invasion of Time)

The Doctor would later mock the Vardans as the only race ever to have been outwitted by the Sontarans.

Mortimus would utilize Artemis, a Chronovore, to release Varda from the time loop and suggested that they invade Earth in 1976. This invasion was also defeated by the Doctor, who trapped them in a standing wave, then beamed them back to Varda. When the invaders arrived home 5000 years later, they found that a government revolution had occurred during their absence and that their race had abandoned military conquest. (NA: No Future)

At least one refugee Vardan remained peacefully on Earth after the invasion. (NA: Return of the Living Dad)