Stone Dalek

The Stone Dalek was one of the progenitor Daleks.

History
The stone Daleks were the Progenitor Daleks present at The Alliance's sealing of the Doctor in the Pandorica in 102 A.D.. As the cracks in time continued to run rampant across the Universe, Dalek history was erased, leaving the stone Daleks as 'after images'. The Pandorica contained atoms from the original universe, from before the cracks started to erase events, and had the ability to sustain life. Light from within the Pandorica reactivated one of the Daleks, albeit with limited power. The Dalek to shot the Doctor, managing to severly wound the Time Lord, but at the cost of depleting it's energy reserves. It was then confronted by River Song. Initially disbelieving that River would destroy it, based on the fact that she was one of the Doctor's companions, after checking it's records and discovering who she was. The Stone Dalek, realising River would kill, begged (out of character for a Dalek) for mercy. River did not heed it's request, and shot it through the eyestalk with an Alpha meson gun, killing it. When the Doctor reset the universe and timeline, the Stone Daleks were presumabley restored to their original form and place in space and time. (DW: The Big Bang)

Behind the Scenes/Trivia

 * It is unknown what Progenitor Dalek it is, it could be a Drone, Eternal, or Supreme. The voice of this Dalek isn't as deep as the Supreme's, so it may be one of the former.
 * This Dalek has been noted to be more ruthless and "trigger-happy", which many fans believe a Dalek should be like.
 * The Stone Dalek does not say much other than the basic "exterminate!" and when it's talking to River Song it shouts out "Mercy!" and also including "Restoooring!" when it was damaged by Rory and River Song.