Sentreal

Sentreal, from the planet Sentreal, (PROSE: Mission to the Unknown) was a representative of his home galaxy at the first meeting of the Galactic Council. (TV: Mission to the Unknown)

Appearance
Sentreal was a tall half-animal, half-vegetable being like an animated tree, PROSE: Mission to the Unknown) all black apart from two burning bright eyes in his cylindrical head atop which was a black crown. His body resembled several open cones stacked on top of each other, (TV: Mission to the Unknown) which the Fourth Doctor remarked looked like a Christmas tree. In truth, these cones could spin at violent speeds to kill enemies. (AUDIO: The Perfect Prisoners)

Sentreal himself commented that his head looked like a chess piece with a concertina section, which allowed him to bobble up and down to express agreement or disagreement. (PROSE: Sentreal)

Biography
In 4000, Sentreal served as a delegate to the Galactic Council and, along with the other representatives of the outer galaxies, allied himself with the Daleks in their plan to conquer the Solar System, (TV: Mission to the Unknown) before realising he was at the wrong meeting, when he intended to be at the Intergalactic Peace Conference of Andromeda. (PROSE: Sentreal) As such, he did not appear at the seventh meeting, his place taken by Zephon, Master of the Fifth Galaxy. (TV: The Daleks' Master Plan)

Later in the 41st century, Sentreal did became a member of the Syndicate, composed of other former members or relatives of members of the Galactic Council. He attacked Ann Kelso, but she was able to control him with a dream machine, and used him to kill Trantis III before ordering Sentreal himself to jump out a window, where he fell to his death. (AUDIO: The Perfect Prisoners)

Behind the scenes

 * The actor who played Sentreal did not receive a credit, but Johnny Clayton and Len Russell played "Alien Delegates", while Pat Gorman played a "Planetarian". It remains unclear, to date, which of them played Sentreal. Christopher Naylor voiced the role in the Big Finish audio The Perfect Prisoners.
 * Prior to the recovery of episode two of The Daleks' Master Plan, Sentreal and Beaus were often misidentified with each other, including in the novelisation.