Monster Files: Sontarans

The Sontarans are a race of humanoids with a stocky build, greenish brown skin, and a distinctive dome-shaped head. Ross Jenkins in "The Sontaran Stratagem" describes a Sontaran as resembling "a talking baked potato" but The Doctor sticks up for the Sontarans by saying to them he looks like a pink weasel.

Sontarans come from a large, dense planet named Sontar in the "southern spiral arm of the galaxy" which has a very strong gravitational field, which explains their compact stocky form. They also are far stronger than humans.

Although physically formidable, the Sontarans' weak spot is the "probic vent" at the back of their neck, through which they draw nutrition. It is also part of their cloning process. They have been killed by targeting that location with a knife, a screwdriver and an arrow, even something as simple as a squash ball aimed at that point is capable of incapacitating them temporarily ("The Sontaran Stratagem"). They are also vulnerable to "coronic acid",