Alpha Dalek (Resurrection of the Daleks)
From Tardis Wiki, the free Doctor Who reference
Following the Dalek-Movellan War, the Alpha Dalek was a grey Dalek subordinate to the Supreme Dalek in 4590. It considered the Supreme to be "effete."
During the Duplicate Incident, Alpha confronted the Daleks conditioned to serve Davros in a London warehouse in 1984. When the Gamma Dalek insisted that "Davros must be honoured", Alpha opened fire and exterminated Gamma, only for Gamma to land a hit and exterminate Alpha as well. (PROSE: Resurrection of the Daleks)