Mutant Dalek embryo

The Mutant Dalek Embryos were failed attempts at creating new Daleks on 1930s Earth. The creatures vaguely resembled Kaled mutants, though the lack of eye and tentacles gave them a more brain-like appearance. Being the last Daleks in existence,. Initially, they attempted to breed new dalek mutants with genetic material extracted from the members of the Cult. Their experiments were unsuccessful, inadequate power supplies preventing them from creating sustainable life.(DW: information from the dalek handbook) The resulting lifeless genetic matter was discarded in the nearby sewers.The Cult moved on to converting Humans into Human-Daleks in the Final Experiment and the embryos were dumped in the sewers to die in the dark. This is where the Doctor found one, which alerted him to the Daleks in Manhattan. (DW: Daleks in Manhattan)