The Hybrid
The Hybrid was a creature thought to be crossbred from two warrior races according to prophecies from the Matrix. The two races assumed to be The Hybrid were the Daleks and the Time Lords. (TV: Hell Bent)
References
Davros attempted to transform some of his Daleks into Time Lord hybrids, intending to fulfil an ancient Gallifreyan prophecy which warned of a Dalek-Time Lord Hybrid that would conquer Gallifrey. (TV: The Witch's Familiar) However, the Twelfth Doctor later claimed that the Daleks would never allow anything to be "half Dalek" and that the hybrid of Time Lord prophecy was "Me". (TV: Heaven Sent) He later shared this theory with Me, at which point she countered with the theory that either he singly was the Hybrid or if the Hybrid could be interpreted as being more than one being-the pair of the Doctor and his companion Clara Oswald who would destroy time by saving Clara's life after she was extracted from her death from the chronolock. Another theory was that the hybrid might be The Doctor and The Master (or The Mistress). (TV: Hell Bent, Face the Raven)