Supreme Dalek (Victory of the Daleks)

A white Supreme Dalek served as second-in-command to the Prime Minister of the Parliament of the Daleks.

Biography
The Supreme Dalek had a significantly diminished role in the Parliament of the Daleks, merely maintaining a token presence. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)

When the Prime Minister made a request to the Eleventh Doctor, Amy Pond and Rory Williams to save the Daleks from the Dalek Asylum, the Supreme Dalek informed the Doctor of the alias the Daleks use to refer to him, "the Predator", and some of the information regarding their mission to the Dalek Asylum. Just as the Parliament was about to destroy it, Oswin Oswald removed any memory of the Doctor from the Daleks' Pathweb from the centre of the Asylum, causing the Supreme Dalek, along with all other members of the Parliament, to forget the Doctor entirely. (TV: Asylum of the Daleks)

When the First Question was transmitted from Trenzalore across the universe after the Eleventh Doctor translated it, the Supreme Dalek recognised it as the voice of a Time Lord. After the Daleks regained their memories of the Doctor from converting Tasha Lem into a Dalek puppet, the Supreme Dalek exterminated the Prime Minister of the Daleks after deeming it unfit for purpose.

Following the Prime Minister's extermination, the Supreme Dalek served as leader of the Daleks throughout the rest of the Siege of Trenzalore. It piloted the Parliament of the Daleks to Trenzalore to exterminate the Doctor, but was destroyed, along with all the other Daleks, after the Doctor gained a new regeneration cycle from the Time Lords. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)

Behind the scenes

 * The Supreme Dalek in Asylum of the Daleks was depicted using a specially created prop.