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 the real "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) While on Earth, they were able to convincingly disguise themselves as humans. (AUDIO: The First Sontarans)

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)

A group of Kaveetch, including Meredith Roath, the creator of Sontaran clones, used their time travel technology to arrive at 19th century Earth, where they were being pursued by the clones and were forced to enter into a makeshift alliance with the Rutans. They were assisted by the Sixth Doctor and Peri Brown, who helped them relocate to a different planet. (AUDIO: The First Sontarans)

During either the 25th or 26th century, after the destruction of Sontar by the Rutans, the Sontaran clones 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)

Later, the Tenth Doctor and Rose Tyler encountered Snathe, a pureblood commander of the Betrothal of Sontar, a Sontaran mining ship. (COMIC: The Betrothal of Sontar)