The Lurons are a spacefaring humanoid species with yellow skin, pointed ears and sharp teeth. After their homeworld became uninhabitable, the last survivors of the race set off in a huge flying saucer to colonize a new world.
Their technology is vastly advanced, giving them the ability to create localized time bubbles (within which time can pass slower or faster than outside), instantaneously replicate living creatures, and even miniaturize their home system's old sun, which they keep contained in a dimensional wall inside their spaceship and use as a nuclear reactor.
The Luron sun notably emits deadly amounts of radiation. Although the Lurons can physically tolerate this, and are able to survive as well with it or without it, the radiation is known to affect their minds in a subtle way, making them more hostile and immoral than they would normally be.
- Big Finish's Doctor Who, The Lost Stories – The Valley of Death (Fourth Doctor, 2012)