5. The Cyberking - The Next Doctor (2008)
The 2008 Christmas Special The Next Doctor not only gave us the bizarre Cybershades (animal Cybermen) but also the Cyberking. One of the most over the top yet underwhelming monsters in recent years, which proved that size is no guarantee of quality. Irish actress Dervla Kirwan is pretty good as the Cyberking's human processor Mercy Hartigan but a steampunk Cyberman that is several storeys tall going all Godzilla on Victorian London is a sight that can inspire little more than sniggering and mild embarrassment. A steampunk Cyberman is an interesting concept. Doctor Who meets Transformers is not. It was too bombastic and over the top for what was largely a pretty low key and character focussed episode that would have worked much better with a more subtle climax. It was a monster so ludicrous that it was retconned out of existence a year and a half later in the Series 5 episode Flesh & Stone and has yet to make a return appearance after nearly five years.