Dalek mutant

Kaled mutants were the mutated descendants of the near-human Kaleds of the planet Skaro. Enclosed in protective armour and weaponry, they became the organic parts of the Daleks, mounted in the upper parts of the Dalek travel machines.

Biology
Kaled mutants often varied in appearance, though kept the same basic structure of an octopoid species with a comparatively large brain. Their young were globular, soft and shapeless with several tendrils or tentacles. (DW: The Power of the Daleks, Genesis of the Daleks) Although usually dependent on their travel machines for offense/defense, the bare mutant could be dangerous; Even the young were quite lethal and capable of strangulation with their tentacles, and, in this way, attacked the Doctor. (DW: Genesis of the Daleks) Some mutants were eyeless and green with whip-like tentacles. (DW: The Five Doctors, Resurrection of the Daleks) The Doctor once said that they had a deadly sting, and during a 1984 incursion into London, one of these creatures, separated from its casing, attacked and injured a Human soldier without difficulty. (DW: Resurrection of the Daleks)

During the Imperial-Renegade Dalek Civil War, the Imperial Daleks commanded by Davros were surgically altered, with their appendages physically grafted into their machines. In this, they differed from their rivals, the Renegade Daleks. (DW: Remembrance of the Daleks)

Others, after the Last Great Time War, were pale blue-green or green-brown with one large functioning eyeball and a small vestigial socket. The remnants of a face could be seen, more clearly on some mutants than on others; as well as the functioning eye and the sealed-up eye, a nose and mouth were vaguely discernible. (DW: Dalek, The Parting of the Ways) The mutants created using Human cells produced small, blue-green creatures, apparently consisting purely of a head, with two eyes and an overall clearer "face". (DW: The Parting of the Ways)

Dalek Sec had lower tentacles long enough to grab hold of an adult Human and had an unusual, trunk-like appendage that could envelop and carry a whole adult Human. This may just be a feature of Sec, as no other Post-Time War Dalek, besides the Emperor, has been seen in full. (DW: Daleks in Manhattan)

The mutants on occasion demonstrated an accelerated healing ability in response to localized wounds. One Dalek mutant in particular, while being tortured by Commander Farrow, began to repair its damaged body, its flesh growing over and thereby burning Farrow's hand. (BFA: Jubilee)

The voice of a Dalek was electronic as the actual vocalizations from the mutants amount to little more than squeaking sounds. Without the assistance of their casing, they are unable to produce speech as they do not possess tongues or vocal chords. (DW: Resurrection of the Daleks, BFA: Jubilee) The laboratories where Daleks are made used cells from other Daleks to clone the creatured. This means that one Dalek can produce countless copies of itself during its lifetime; and as a Dalek is reputed to live to be a million years old (although this has never actually been confirmed), it does mean that if only one Dalek survives, then it is quite capable of beginning an entirely new Dalek race by itself.

The mutants have a specific DNA type of 467-989. (DW: Daleks in Manhattan)

History
For an account of the creation of the Daleks, see separate article.

The Thals believed that the Daleks had not yet fully mutated into their final form. (DW: The Daleks) Kaled mutants appeared different over time, and, as noted above, during the war between the Imperial and Renegade Dalek factions, the two sides had physical differences, with Davros' side now altered into true cyborgs and physically made one with their travel machines. (DW: Remembrance of the Daleks)

Other Information
Kaled mutants were quite possibly fatal to a Time Lord when eaten. (EDA: The Scarlet Empress) However, their "Dalek juice" could be ingested with no apparent ill-effect. (BFA: Jubilee)

Behind the Scenes
Though the comic The Dalek Chronicles and other media revealed many "facts" about the Daleks which did not appear on television, the appearance of the inner creatures remained undisclosed until The Power of the Daleks on television, in the form of newly created creatures. They appeared in their adult form in The Evil of the Daleks. Both appeared as eyeless shapeless creatures with tendrils.

They first appeared in colour in Genesis of the Daleks (as young) and as adults in Destiny of the Daleks. The latter story the Fourth Doctor makes statements which imply that the Daleks have now abandoned any organic component and have turned themselves into robots. Future stories did not explain and elaborate and returned to the previous concept of the Daleks as ultimately organic. The Five Doctors showed a lot of the adult Kaled mutant for the first time ever.

From Series 1 onward, the Kaled mutants went through a major re-design. They now had a single eye, more defined bodies and ropy tentacles.