Tivolians were the inhabitants of the planet Tivoli.
History
Tivolians were one of the oldest species in the galaxy. Their home world was conquered multiple times. (TV: The God Complex)
Culture
At first glance the Tivolians were a society of cowards. They never defended themselves and did everything they could to make their conquerors as comfortable as possible. The Eleventh Doctor considered this to be an aggressive form of cowardice. The Tivolians didn't fight; they survived by outliving their conquerors. (TV: The God Complex)
The first ghost in the Underwater base, The Drum, was a Tivoli. TV: Under the Lake