Gibbis

Gibbis was a native of Tivoli, a grey planet whose residents took a strange delight in subjugation.

Biography
Before he was plucked from Tivoli and deposited in a hellish "hotel", Gibbis worked in town planning. He was engaged in a project to line all his planet's highways with trees so that invading armies could march in the shade.

After his escape from the hotel, Gibbis requested that the Doctor drop him off in the TARDIS a galaxy or two away. With the Prison Ship already in visual range of Gibbis, this may imply that Gibbis had chosen to leave Tivoli. (DW: The God Complex)
 * The name of the Tivoli native species remains undisclosed.

Personality
He was a coward, a trait of Gibbis' species, the Doctor described it as an aggressive sort of timidity. Gibbis was prepared to sacrifice Howie Spragg in the name of self-protection and showed a sadistic pleasure in unnerving Amy when he suggested she might have not yet have entered 'her room'. (DW: The God Complex)