Didoan

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

Culture
The Didoans were a very peaceful race, as their small population made any violence a threat to their survival. They had ceremonial clothes resembling an insectoid creature which they wore on special occasions. These clothes consisted of a headdress with antennae, eyestalks, mandibles, and spikes around the neck; black robes; clawed gloves with spiked wrists; and clawed shoes with spikes around the ankles.

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 Bennett, he backed away in fear and fell from a rock ledge to his death.

After the First Doctor's TARDIS left Dido, the captain of the approaching Earth rescue ship contacted UK-201 again, asking for the homing beacon so he could find the planet. However, the Didoans wrecked the communications system so the rescue ship would never arrive. (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)