Scientist Dalek (The Guide to the Dark Times)

A unique Scientist Dalek was a member of the Time Squad, a battalion of Time-Sensitive Daleks deployed by the Emperor to attempt to make history more favourable to the Daleks after a divergence in the timeline was detected, (PROSE: The Guide to the Dark Times) which rewrote time, making it so the Daleks had not fought the Last Great Time War. (COMIC: Defender of the Daleks)

Physical appearance
The Scientist's casing was a unique Dalek variant: it had the broad design of a Bronze Dalek but had a dark, gunmetal-grey base unit and grating section, and a crimson dome, sense globes and slats. Its eyestalk's lens was a bluish white with small green, yellow and blue lights surrounding it, while its luminosity dischargers were yellowish. Instead of the familiar plunger-like structure, its manipulator arm ended in a six-fingered "claw". (PROSE: The Guide to the Dark Times)

Biography
After the Time Squad recruited the Eighth Doctor, the Scientist travelled with the Time Commander, Prime Strategist and Executioner to Wrax. Whilst the Doctor and Strategist went to examine the Wraxians’ gallery, the three Daleks met the President of Wrax, offering an alliance and asking for a demonstration of the Wraxian superweapon, the Devolver. She agreed however betrayed the Daleks and trapped the three, intending to use the Devolver against them. The Doctor made an agreement for the Daleks to withdraw in return for the Devolver’s dismantling, with the Scientist returning to the Squad’s timeship. (AUDIO: The Enemy of My Enemy)

Psychological profile
Melody Malone described the Scientist Dalek as "a whizz with temporal science". It was not only time-sensitive, but had a strong sense of how actions could affect both the future and the past, allowing it to use "time itself" as a weapon when devising "new and unusual plans" in conjunction with the Dalek Prime Strategist. (PROSE: The Guide to the Dark Times)

Behind the scenes

 * Speaking of his portrayal as the Scientist, Nicholas Briggs described him as "very very picky and pedantic".