Kaveetch

The Kaveetch or pureblood Sontarans were the original natives of Sontar. They were natural-born members of their species and did not use mass cloning techniques.

They also considered themselves to be "Sontarans" (in parallel to humans being "Earthlings"), and preferred not to refer to the clone race commonly known as the Sontarans as such, using the name "Sontaran clones" instead. (AUDIO: The First Sontarans)

Biology
Unlike the Sontaran clones, the Kaveetch reproduced naturally. They appeared more gangly and more like humans. (AUDIO: The First Sontarans, COMIC: Pureblood)

History
At some point in their history the Rutans attacked Sontar and it started a war between the Rutans and the Kaveetch. The Kaveetch were losing the war so they began to clone themselves to replenish the soldiers they lost. The clones eventually became the Sontarans and the Kaveetch were forced to leave Sontar. (AUDIO: The First Sontarans)

During either the 25th or 26th century, the Rutans destroyed the Sontaran homeworld, Sontar, with photonic bombs, though some escaped with the Sontaran racepool. At the same time, the Sontarans encountered a surviving group of pureblood Sontarans. Due to the intervention of the Seventh Doctor, the cloned and pureblood Sontarans decided to pool their resources. (COMIC: Pureblood)