Nimrod

Originally one of a tribe of mammoth herders during prehistory, Nimrod encountered the alien survey team headed by Light. Light captured Nimrod and intended to keep him preserved as the last specimen of his species. Josiah Samuel Smith later awoke him and employed him as a butler. Serving in this position, he encountered the Doctor and Ace there in 1883, who set about winning his trust.

Nimrod at first revered "the Burning One" (Light) as a god as had his tribe. By accident, Nimrod himself broke the membrane sealing Light into stasis. At first stunned, he lapsed into a coma until roused by the Doctor. Nimrod's servility crumbled and he re-lived the old days of his tribe and their worship of Light. No longer a servant to either Light or Smith, he decided to leave Earth along with Control and Redvers Fenn-Cooper to explore the stars. (DW: Ghost Light)