Sontaran

The Sontarans (pronounced "Sohn-TAHR-ans") are a belligerent and militaristic clone race who waged a long conflict against the Rutan Host.

Appearance
Sontarans were humanoids with large, bulbous heads and stocky bodies. They had grey-brown skin and deep set features and all appeared roughly the same age, with the exception of General Sontar. (PDA: The Infinity Doctors)

Sontarans had three digits on each hand (two fingers and a thumb). They were strong and tough in environments like Earth or Gallifrey, which had lower gravity than Sontarr. Sontarans had green blood. (DW: The Two Doctors) There were no female Sontarans, since they rely on cloning. (DW: The Time Warrior)

At least one, Sontaran, Styre, had five digits (four fingers and a thumb) on each hand. This, along with facial variation seen in the species, indicates some degree of individuality even between clones. (DW: The Sontaran Experiment)



Weaknesses
Despite their strength, Sontaran muscles were designed for load bearing rather than leverage, which means they can be easily tied up. (DW: The Time Warrior)

One of the few ways to hurt or kill a Sontaran is via a small access port called a "probic vent" at the back of the neck. (DW: The Time Warrior) They are also weak to Coronic acid, which causes them to disintegrate and burn. (DW: The Two Doctors)

Technology
The Sontarans were reasonably advanced, though all their technology was designed for use in the war with the Rutan Host. They often used spherical spaceships and can make advanced robots for various purposes. They can use and make a wide variety of hand-held weapons, though they usually use a thin, rod-like energy weapon designed for the Sontaran hand. This energy weapon is used for energy projection and hypnotism. (DW: The Time Warrior) They can create around a million clones every four minutes, (source?) which allows them to sustain massive casualties. By the 12th century, Sontarans had achieved crude time-travel technology utilizing osmic projection though not on par with the Time Lords. (DW: The Time Warrior) They have been seen trying to obtain  more effective time-travel technology. (DW: The Two Doctors)



Sontarans were typically seen wearing their distinctive battle armor, which resembles a thick grey space suit. Their helmets are dome-shaped and almost featureless except for two eye holes and a small, flat crest running from the forehead to the back of the neck. They generally carry around their rod-like weapon and a translating device. (DW: The Time Warrior)

History
The Sontarans were engaged in a destructive war with the Rutan Host and have been for millions of years. They were already engaged in the war during the Millennium War, though they briefly joined forces during it. (DW: The Quantum Archangel)

During the 12th century a Sontaran scout landed on Earth and claimed it for the Sontaran Empire. He then brought scientists from the future into the past in order to repair his ship. (DW: The Time Warrior)

In the 1980s, the Sontaran Warburg investigated the possibility of using TARDIS-like time ships in order to win the war. At the same point in time they were involved in a battle with the Rutans in the Madillon Cluster. Neither attempt was successful. (DW: The Two Doctors)