Yarvelling

Yarvelling was a famous Dalek scientist.

Creating the War Machines
Under the orders of Minister Zolfian, he developed a mobile war machine for the war against the Thals which he dubbed the Dalek War Machine. Zolfian ordered the mass production of such machines to be readied. However, during the war, a freak meteorite storm detonated the neutron bombs built and stashed away by the Daleks. Zolfian and Yarvelling survived in the war council chamber, turning into a fallout shelter, and were believed to be the only unmutated survivors of their kind, (COMIC: Genesis of Evil) although in truth several other individuals had survived in stasis. (COMIC: Legacy of Yesteryear)

Hiding out & death
For two years following the final act in the war between the Daleks and the Thals, nothing stirred on Skaro. Believing radiation levels to have dropped sufficiently, Zolfian and Yarvelling finally emerged from their shelter; where Zolfian's main ambition was to destroy any surviving Thals, Yarvelling was more worried about locating surviving Daleks.

However, they quickly found the surface of Skaro to be devastated, and contracted radiation sickness themselves. They were discovered by a mutation, the first member of the race the rest of the universe would soon know as the Daleks; Yarvelling realized with fascination that the creature it had become was "a thousand times superior" in intelligence to himself and Zolfian, and observed that, being "all brain", it had taken to inhabiting the very war machine Yarvelling had developed, using it as a travel machine and a protection against the radiations. Before they died, Yarvelling and Zolfian rebuilt the war factory, started a Dalek production line, and made a special casing for the first Dalek, who would soon declare itself the Dalek Emperor. The two humanoids died of radiation sickness just as the casing was completed. (COMIC: Genesis of Evil)

Legacy
At a much later point in Dalek history, the Dalek Prime's Daleks knew that despite claiming otherwise, Davros had not actually invented the Dalek travel machine, having instead stolen the designs of "other scientists". (PROSE: War of the Daleks)

Something akin to the story of Yarvelling, Drenz and Zolfian was one of the creation myths formulated by species conquered by the Daleks about their oppressors. The myth, however, altered certain details, speaking of the "Sea of Ooze" and suggesting the Dalek War Machines were originally intended to be autonomous robots. Human historians who recorded the myth at length in their history of the Daleks did not give it much credence, though they granted that, for one moment at least, the Yarvelling story may have briefly "become" the true origin of the Daleks at one point during the Last Great Time War. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)

The black, friable spires of Yarvelling's Church from Skaro were a fragment of the Last Great Time War. According to one account, the Eighth Doctor saw the Cathedral fused with fragments of Morbius' Red Capitol in the backwater where he triggered the Moment. (PROSE: Doctor Who and the Time War)

Behind the scenes

 * According to The Dalek Dictionary feature in The Dalek Book, Yarveling (with one "l") was the first to travel to Flidor and bring back gold (Flidor gold being one of the main components in the casing of the first Dalek Emperor). He also discovered silcronian and a method for water compression.
 * Yarvelling's status as the original creator of the Dalek travel machines was seemingly contradicted by the introduction of Davros in Genesis of the Daleks, although the novel War of the Daleks hinted at a possible reconciliation by having the Daleks themselves explain that Davros only created the Mark III Travel Machines based on designs stolen from "other scientists".
 * Davros' half-sister Yarvell, who appeared in I, Davros, was named after Yarvelling.