Qetesh

The Katesh were a species that fed off excitement in peoples lives. (SJA: Goodbye, Sarah Jane Smith)

Biology
The Katesh outwardly resembled humans, though they possessed far greater strength. Their stomachs existed outside their bodies.

History
The Katesh banished one of their number, whose hunger was greater then any other, to a prison ship, with only a games console for entertainment. The prisoner managed to reprogram the device to serve her needs, turning the prison into a ship. She went to many planets draining their inhabitants completly.

When she came to Earth, she posed as a human named Ruby White. Getting close to Sarah Jane Smith, who led the most exciting life on Earth, she managed to weaken and lock her in a basement with her stomach as it slowly drained her.

Luke Smith defeated the Katesh by using her device (dubbed "Mr White") to simulate meteors falling to earth on a large scale, causing six billion people to have "thrills" and overloading Ruby White's stomach. Ruby was then returned to her prison by a restored Sarah Jane, but vowed revenge on her and the entire planet. (SJA: Goodbye, Sarah Jane Smith)