Black Dalek (The Apocalypse Element)

A Black Dalek led the Daleks in the invasion of Gallifrey.

He was responsible for the devastation of Archetryx causing Etra Prime, the oldest planetoid in the universe, to crash into it. His mission was to recover the Transference Crystal by orders of the Emperor and activate the Apocalypse Element. Before dying, he explained to the Doctor that they had created a Galaxy, which was four times the size of the Milky Way galaxy and home to over six hundred billion stars, to occupy, conquer Mutter's Spiral, destroy countless inhabitants and become "the Masters of infinite Skaros". (AUDIO: The Apocalypse Element)

Behind the scenes
Although described in dialogue as simply a Black Dalek, the Dalek leader in The Apocalypse Element was illustrated on the cover with a unique design: instead of an all-black colouring, it had a colouration similar to an Imperial Guard, with a black dome and a silver base, and a red lens on its eyestalk.