Gog

Gog and Magog were Great Old Ones. (PDA: Divided Loyalties) In Earth's mythology they were known as giants. The Doctor had believed that this myth was inspired by the Ogri of the Nine Travellers (REF: Doctor Who: Creatures and Demons), when he said, "Gog, Magog, ogres" (DW: The Stones of Blood).

The Doctor encountered an individual called Magog in a parallel universe. (DWM: The Iron Legion)

Behind the scenes

 * Gog and Magog is originally a Biblical reference. The Doctor, however, is referring to English legends.