Dalek Puppet Emperor

Dalek Puppet Emperors were a type of Dalek leader. During the time leading up to the Last Great Time War, a Puppet Emperor openly declared his hostility to the Time Lords of Gallifrey. (PROSE: Meet the Doctor)

Behind the scenes
Meet the Doctor does not identify the specific "Puppet Emperor" who declared hostilities, not elaborate on the nature of the position. It may be related to the concept of Dalek Emperors being functionally "puppet leaders" because the Daleks would turn on their leader at the first sign of deviation from Dalek conformity, restricting their decision-making immensely; this is an idea that Russell T Davies has personally espoused.

If one indeed takes "Dalek Puppet Emperor"s to refer to Dalek Emperors in general rather than some specific class or type thereof, the Dalek Pupper Emperor who "openly declared his hostility to the Time Lords of Gallifrey" may be Davros, who voiced intent for his Imperial Daleks to "sweep away Gallifrey and its incompetent quorum of Time Lords" in Remembrance of the Daleks, or his successor who actually led the Daleks into the Last Great Time War (whose identity depends upon accounts between a resurrected Dalek Prime, a newly-promoted Supreme Dalek known as the Emperor of the Restoration, or potentially an advisor of the Restoration Emperor known as the Dalek Prime Strategist).