Morok

Moroks were a humanoid race who founded the Morok Empire. However, like all great empires, they soon fell into decline.

History
The Moroks set up a Space Museum on Xeros to celebrate their victories. They killed many Xerons, leaving only the children alive. When they were old enough they were sold into slavery. The First Doctor and his companions aided the Xerons in their revolution against the Moroks. They killed the Museum's curator, Lobos. With the planet free, the Xerons destroyed the Museum. (TV: The Space Museum)

The Monk was once a technical adviser to the Moroks. (PROSE: No Future)

The Morok Empire collapsed in the 30th century due to human intervention. (PROSE: The Death of Art)

While holding an auction for the Face of Humanity, Fegovy created the holographic illusion of two Moroks to increase the sale price. (PROSE: Fegovy)

The Xaranti ship that invaded Earth in the 1970s was a modified Morok battlecruiser. (PROSE: Deep Blue)

Behind the scenes

 * Amongst other things, the documentary Defending the Museum explored Robert Shearman's view that the Moroks are intended to parody the quintessential Hartnell-era foes. He evidenced this by suggesting Morok to be a spin on moron and examines their dull-witted behaviour.
 * If the coloured cover-art to the audio television soundtrack release for The Space Museum is to be taken as canonical, it can be suggested that the Moroks have bright red hair. Though, this is conjectural at best, and may simply be the product of the artist's free-reign on the cover's design.