Tzun

The Tzun were a humanoid race native to S'Arl.

Technology
The Tzun used the Tzun Stormblades as spaceship. These Stormblades had graviton shielding and terullian hulls. (MA: The Dark Path)

History
The Tzun were a spacefaring species by at least 23,000 BCE. Shortly after developing space travel, they fought the Darklings of Yuggoth, which corrupted their DNA. They perfected genetic engineering and began integrating new species into their Confederacy by combining their DNA with theirs.

In 1957, the Tzun attempted to invade Earth with the aid of the Master, but were defeated by the Doctor. (NA: First Frontier)

In 1983, a Tzun, nicknamed Tony, was a member of Isaac Summerfield's team. (NA: Return of the Living Dad)

In 2172, the Tzun attempted to conquer the Veltrochni. (NA: First Frontier) Though the Tzun were successful at the beginning, as the war carried on the Veltrochni packs joined forces and fought back. They drove the Tzun off, destroyed many of their colonies planets and effectively collapsed the entire confederacy. The Veltrochni became renown for their power after this. (MA: The Dark Path)

If Tzun crashed at Roswell as well as Seruba Velak, then they could be one of the two spacecrafts that attack her ship.

Other References

 * The Tzun were one of the species that Professor Hamilton Smith had theories on. (BNA: Dry Pilgrimage)
 * The Tzun were mentioned by the Doctor as an example of hostile aliens, alongside Daleks. (PDA: Salvation)