Sontarans come from a planet with surface gravity many times that of Earth, resulting in their squat, powerful bodies. They have dome-shaped heads with no neck, beady eyes and tufts of wiry hair. Their hands have three thick fingers, and their skin is brown and leathery. They travel in spherical spaceships, and wear metallic silver armor with a removable helmet. All Sontarans are clones - although the clone template appears to change over time - and newborn Sontarans are called "hatchlings". Their cloning technology is so advanced that they can multiply at a rate of a million Sontarans every four seconds. Sontarans are extremely methodical, as well as quite egotistical. They have very keen vision, and can easily make out physiological differences between gender and species. When threatened, they hiss.
Sontarans attend a military academy, probably as preparation for their great war. Fighting is done in units, and all Sontarans report to the High Command. Military manoeuvres are overseen by the Grand Strategic Council. A Sontaran Special Space Service also exists, although its purpose is unclear; it may have something to do with invasions of planets. Their battlefleets fly in an arrow formation.
The Sontarans' primary enemies are the Rutans, with whom they have been battling for a very long time. In an effort to obtain an advantage, the Sontarans try to seize control of strategically-located planets, one of which happened to be Earth. Prior to invasion, Sontarans carry out military assessment surveys. Rank forms the Sontaran hierarchy, which includes Field Major, Marshal and Grand Marshal. Their military background has given them great respect for honor, and honor can be maintained through use of the traditional duel.
Sontarans are very technologically advanced. They can construct simple robots and androids, use an ocular device for hypnotizing their workforce, project themselves forward in time using a frequency modulator, affect human minds with a head-mounted device, set up effective forcefields, and understand other languages using a translator dial. Sontarans arm themselves with wand-like ray guns, which envelop their victims in a red glow, and which can be modified to affect the human mind and make someone tell the truth. They also have large cutting devices on hand. Their ships use deadly photonic missiles. Probably their most horrific weapon is a kind of grenade that can destroy an entire galaxy.
Certain sound frequencies seem to cause Sontarans pain, although they are not fatal. Sontarans must feed on pure energy, a process with apparently involves the tellurian diode bypass transformer in their ship. If this is removed, when the Sontaran next tries to feed, the ship will vaporize and the Sontaran will be consumed by the energy. A Sontaran's main weakness is the probic vent, located at the back of the armor. One blow there effectively stuns a Sontaran; if pierced by an arrow or knife, the Sontaran will die. They can also be killed by coronic acid.
