Necros Dalek

The Type VI Dalek was a model of Dalek casing identified by the Time Lords. They were an early prototype of the Imperial Daleks. (PROSE: Dalek Combat Training Manual)

Appearance
In contrast to the drab grey and black Renegade Daleks, the sleeker Imperial Daleks had casings with white livery with gold sense globes and high-pitched, scratchy voices. The prototype models built by Davros on Necros retained the classic eyepiece and plunger manipulator arms, but also featured rounder bases. (TV: Revelation of the Daleks)

History
Davros created a new race of Daleks at the Tranquil Repose funerary complex on Necros, using parts from cryogenically frozen bodies. Some, like Arthur Stengos, he decapitated, modified and placed — still living — into a Glass Dalek casing. During the conversion process, Stengos' personality alternated between that of a human and that of a Dalek. (TV: Revelation of the Daleks)

Davros created several thousand of these Daleks. (PROSE: Revelation of the Daleks) Orcini set off an explosion in Davros' bunker, killing many of the prototype Imperials. Other Daleks loyal to the Dalek Supreme then apprehended him to take him to Skaro for trial. (TV: Revelation of the Daleks)