Minotaur (species)

Minotaurs were a species that fed on faith. They were related to the Nimon.

Biology
The Minotaur was a large humanoid species with hoof-like hands and feet and five horns on their heads. They fed on faith, which caused death when they drained it from their host. They could not feed on a person who held no strong beliefs, such as Rory Williams. (TV: The God Complex)

History
The Minotaurs fed on the faith of other life forms and survived by descending on primitive planets and setting themselves up as gods, feeding on the worship of the natives. Once the species became advanced, they expelled them when they realised that the Minotaurs were frauds.

One Minotaur was trapped within a prison ship, where it fed on victims pulled in from multiple species until the Eleventh Doctor encountered and defeated it. (TV: The God Complex)