Didoan

The Didoans (also known as Dido people) were a peaceful humanoid race native to Dido.

History
When the spaceship UK-201 crashed on the planet in 2493, the Didoans met with the surviving passengers, but were killed along with them in an explosion engineered by Bennett to cover up a murder he had earlier committed aboard the ship. At least two Didoans survived, and when they confronted him, he backed away in fear and fell from a rock ledge to his death.

After the First Doctor's TARDIS left Dido, the Didoans wrecked the spaceship's communications system so that the approaching Earth rescue ship would never find the planet. (TV: "The Rescue")

Behind the scenes

 * The Rescue doesn't give us a clear, one-word for "a being from the planet Dido". The name Dido people is what the First Doctor directly called them in "Desperate Measures". The Time-Travellers' Guide refers to them as Didoi. In The Crash of the UK-201, they are referred to as Didoans.
 * The appearance of the two Didoans in "Desperate Measures" is never explained.
 * The two Didoans were played by John Stuart and Colin Hughes, who remained uncredited both on-screen and in Radio Times. (DWM 325)