Cheetah Planet

The Cheetah World was a mysterious sentient planet and home to the Cheetah People and Kitlings.

Astronomical Data
The Cheetah World had a red-tinted sky and red sun. It had rough terrain, featuring rocks and sand. Due to the Cheetah People and Kitlings living there, it was covered in bones of dead humans and other creatures of the galaxy. There were also the ruins of an earlier civilisation. (TV: Survival) The atmosphere was rich in Artron energy. (PROSE: First Frontier)

The planet was in some sense, sentient and empathic. It was connected to the Cheetah People. When the Cheetah People fought, the planet became unstable and started to destroy itself. The water on the planet had healing properties for the Cheetah People. The world allowed the Cheetah People to teleport to other planets to bring back prey. It also allowed people who wished to come home enough to return by teleportation. Near-humans such as humans and Gallifreyans slowly began to metamorphose, turning aggressive and physically changing into Cheetah People. The Master described the world as dying because of its inhabitants' aggression. (TV: Survival)

Life Forms
The Cheetah People were the dominant species, along with the Kitlings, who were used as part of their teleportation powers. They rode horses, though whether they were native was unknown. (TV: Survival)

History
At some point before the 20th century, an unknown civilisation tried to conquer the planet. They bred the Kitlings to be their eyes and thought they could control the planet, but they were wrong. They too were turned into Cheetah People, leaving only the ruins scattered around the landscape.

Around 1989, the Master found himself on the Cheetah World. He tried to escape by kidnapping humans from Earth, planning to use them to teleport himself to Earth. He finally did so with Midge and escaped to Earth. He was brought back to the Cheetah World with the Seventh Doctor. During a physical struggle between the Doctor and the Master, earthquakes shook the planet, implying that it may have destroyed itself, though the Doctor told Ace that she still carried the planet inside her. (TV: Survival)