Cybermen are iconic villains from the British science fiction television series Doctor Who. They are depicted as humanoid cyborgs, originally human but transformed through technology to become emotionless beings focused on converting others into Cybermen. Their chilling catchphrase, 'Delete!', reflects their relentless pursuit of perfection and their desire to eliminate anything they perceive as inferior. First introduced in the 1960s, Cybermen have evolved in design and storylines, becoming a staple of the Doctor Who universe. They represent themes of loss of humanity and the dangers of unchecked technological advancement, making them a compelling and enduring adversary for the Doctor.