- You may be looking for the minotaurs of Greek legend.
Minotaurs were a species that fed on faith. They were related to the Nimon.
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)
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.