Eternal Dalek
From Tardis Wiki, the free Doctor Who reference
The Eternal Dalek was a yellow, angular eyestalked Dalek and a rather mysteriously named of the new Dalek Empire. It was created by the Progenitor and worked some of the machinery inside the Dalek ship. It escaped through the time corridor with the White Supreme Dalek, Strategist Dalek, Drone Dalek and Scientist Dalek. (DW: Victory of the Daleks)
Behind the scenes
The Eternal's name was given by Steven Moffat in Doctor Who Confidential.
Steven Moffat wanted to try and create a episode story based on this.