The Lurons were an alien race.
Lurons were small and yellow creatures with heads like a vampire bat.
When their original home world became uninhabitable, they left to find another one. Before leaving, they miniaturised their sun and surrounded it with a dimensional wall, using it as a reactor. Their new home was a hundred light years from Earth.
In 1870, the Luron mothership went into orbit around Jupiter. They sent out a ship, which crashed in the Amazon forest. They created a time bubble in the area, where a month inside equated to about 104 years outside. The Fourth Doctor and Leela joined Edward Perkins' expedition in 1977 to learn the fate of his great-grandfather, Cornelius Perkins. Due to the bubble, Cornelius was still alive. Their contact with the Luron Godrin lead to the attempted invasion of Earth by the surviving remnants of the Luron race. The Doctor and Leela managed to foil their plans.