Alpha Dalek

From Tardis Wiki, the free Doctor Who reference

Alpha Dalek was a designation used by high-ranking Daleks.

Following the Dalek-Movellan War, in 4590, an Alpha Dalek was subordinate to the Supreme Dalek. (PROSE: Resurrection of the Daleks)

Another Alpha Dalek led the Renegade Dalek force on Necros to capture Davros. (PROSE: Revelation of the Daleks)