Glass Dalek

A Glass Dalek was a Dalek variant created by Davros for the reproduction of his Imperial Daleks.

History
In a retelling of his first encounter with the Daleks and First Doctor, Ian Chesterton claimed a Dalek with a glass casing acted as the leader of the Dalek City on Skaro. The Thals hacked it to pieces during an assault on the City. (PROSE: Doctor Who in an Exciting Adventure with the Daleks)

In Tranquil Repose on Necros, Davros used the Glass Daleks as part of his experimentation. By placing a cryogenicaly-frozen head into the casing, the head would mutate into the deadly creatures that made up the Imperial Daleks. When the head had become another Dalek, the Glass Dalek casing changed into that of an Imperial Dalek and another glass casing took a new head.

Arthur Stengos almost became a Dalek before his daughter, Natasha, killed him. (TV: Revelation of the Daleks)

Behind the scenes

 * The unrelated Psyche Daleks had a transparent, enlarged dome, but an otherwise normal casing. (COMIC: Emperor of the Daleks)