Viyran

The Viyrans were a race of mysterious beings, infamous for the creation of a variety of biological and viral weapons.

Biology
The appearance of the Viyrans is unknown, as they were always seen to wear white hazmat suits. They appeared to be humanoid, with 3 fingers and a thumb on each hand. They had no real spoken language, but were able to communicate psychically, through hand motions or by trying to replicate an individual's voice. (BFA: Patient Zero)

Technology
It could be speculated that the Viyrans created the Amethyst Viral Containment Station to safely store the deadly viruses that they created. They were known to use flying glass coffins to collect infected patients to try to cure them. They were also capable of time travel. (BFA: Patient Zero) and of modifying the memories of others. (BFA: Mission of the Viyrans)

Diseases
The Viyrans were best known for the diseases they created.
 * One disease was capable of destroying the minds of everyone on a planet. (DWS: No One Died)
 * One disease was a metallic-looking worm which was six inches long. It could induce benefical coincidences. It was capable of transmitting itself through telephones. (BFA: Urgent Calls)
 * Another disease could cause a frenzy. (BFA: Urban Myths)
 * Another disease could grant wishes. (BFA: The Vanity Box, The Wishing Beast)
 * A fifth disease would warp the DNA of the host, slowing killing them. (BFA: Mission of the Viyrans)

History
The Viyrians waged a war with an unknown force, using a variety of viral weapons. Peace was eventually reached, and the biological weapons were gathered together in Amethyst Viral Containment Station, planning to destroy them. A final peace agreement was reached and the biological weapons were gathered together at the Amethyst Viral Containment Station with the intention of destroying them. During an incident with the Sixth Doctor and the Daleks the viruses were spread throughout the universe. They began travelling through the universe, trying to find and cure these diseases. (BFA: Patient Zero)

In 1974, one of the Viyran virus, transmitted through telephone lines, was found on Earth. (BFA: Urgent Calls)