Mede

The Medes were aliens from the planet Mediat. (K9TV: Alien Avatar)

Biology
They were able to project themselves to places where they couldn't physically be. (K9TV: Alien Avatar)

Technology
The Medes were masters of transdimensional transportation, they possessed a staff which allowed both themselves and their ship to be invisible. (K9TV: Alien Avatar)

History
In the year 2050 two Medes came to Earth, they were captured by Inspector Drake and the Department and placed in the Dauntless prison.

Drake then attempted to use their technology in order to spy on the people of London, the attempted replication of their technology caused pollution which leaked into the river Thames. They then attempted to communicate with K9 and the gang by using their Avatar forms to direct K9 to the source of the pollution in the sewers.

June then found and went to the source of pollution, a London warehouse. She then used her higher authorisation to shut down the project, she and the gang then went to the Dauntless Prison and released the Medes, returning their technology and apologising for their capture.

They then removed the pollution from the river Thames and returned home with their spaceship. (K9TV: Alien Avatar)

Trivia
The Medes bare some resemblance to the creator of the Dalek race Davros, with their third blue eye.