Humanoid Dalek

The Daleks were a Skarosian species, who, after a discharge of neutron bombs, mutated into the "machine Daleks". They were, thereafter, known as the humanoid Daleks to distinguish them from their mutated descendants.

Characteristics
These Daleks were short, dwarf-like, blue-skinned humanoids with sparse white hair and disproportionately large heads. One of these Daleks, Yarvelling, described the machine Daleks as a thousand times more intelligent than himself and his ally Zolfian.

At peace with the Thals
These Daleks originated on the continent of Dalazar, situated across the Ocean of Ooze from the home of their enemies, the Thals. (COMIC: Genesis of Evil) As recounted by the Daleks to the First Doctor, in the old days before the neutron war, the Daleks and the Thals were the two humanoid races inhabiting Skaro. They referred to their humanoid ancestors as "Dalek forefathers". In contrast, the Thals believed that the Daleks' humanoid ancestors had been called Dals, (TV: The Daleks) and in his fourth incarnation, the Doctor later encountered humanoid forebears of the Daleks called Kaleds who were fully identical to humans rather than short and blue-skinned. (TV: Genesis of the Daleks)

The Neutron War & near-extinction
The Daleks had a pacifist leader, Drenz, whom the warlord Zolfian personally murdered publicly in order to start using neutron bombs on the Thals and use the new Dalek War Machines invented by Yarvelling against the survivors. Two weeks after the factories of Dalazar commenced production of the war machines, a meteorite strike started a fire in the factories which spread and caused the detonation of the neutron bombs, crushing both civilizations in one fell swoop. For two years, nothing whatsoever moved on the surface of Skaro.

When Yarvelling and Zolfian eventually emerged from the fallout shelter in which they had been keeping hidden, they discovered that radiation had mutated the survivors of their race beyond recognition into the horrific, yet enormously intelligent, Daleks the rest of the universe would soon come to fear. One used one of the prototype Dalek War Machines built by the scientist Yarvelling as transport, making himself into the first "machine Dalek". When, the machine Dalek set them to work on production of more war machines until they died of radiation sickness. (COMIC: Genesis of Evil)

Legacy and survivors
In the time of the Dalek Empire, the Daleks found three pre-war humanoid Daleks in suspended animation and revived them. These humanoid Daleks dubbed their cyborg counterparts "metal Daleks". However, they soon discovered that although they carried on the name and technology of the Daleks of old, the metal Daleks were cruel killers devoid of a conscience, which led to the humanoids' refusing to cooperate with them. The Daleks, finding no further use for their ancestors if it was not to glean secrets that had been lost in the Neutron War, killed all three of them, who took with them the secret of the existence of Earth (which one of them, an astronomer and explorer, had discovered shortly before the war). (COMIC: Legacy of Yesteryear)

Behind the scenes

 * In The Daleks, the Daleks speak of their ancestors as "Dalek forefathers" while the Thals' legend refer to their ancestral enemies as the "Dals". Although there is little to indicate that Terry Nation intended for the two to be understood as separate species with a debate over which of them had evolved into the Daleks, the Dal and Humanoid Dalek species were developed independently by later authors.
 * Yet a third option on the identity of the Daleks' humanoid ancestors was later offered by Nation himself in the TV story Genesis of the Daleks, where the Daleks' ancestors are fully human-like and called Kaleds. However, even within this account, the scientist responsible for the Daleks' genesis, Davros, retains the large forehead and warped inhuman features of the earlier comics Daleks, even if they are now attributed to Davros having been disfigured in an explosion, rather than being natural traits of his species.
 * Dalek: The Astounding Untold History of the Greatest Enemies of the Universe postulates that the history of Humanoid Daleks is either a myth, Dalek history having been adjusted and reinterpreted by a conquered race, or perhaps a consequence of the Time Lords' meddling with Dalek history during the Last Great Time War.