Doctor Who: EVERY NuWho Villain And Monster Ranked Worst To Best

Appear in: The Husbands of River Song, The Return of Doctor Mysterio.

We, of course, wouldn't dare suggest that the secondary antagonists from 2015's Christmas special outshone the infinite majesty of King Hydroflax. However the representatives of the Shoal of the Winter Harmony made quite the graphic impact when one of them, Scratch, calmly split one half of his head open, pluck an object out from inside it, then pass it over to River Song.

They take centre stage the following Christmas - this time successfully infiltrating Earth by basing Harmony Shoal institutes in every major city across the globe, with the aim of supplanting all the world leaders for complete colonisation. We also got to see how Harmony Shoal went about their surreptitious invasion when the boss of the New York branch, Mr Brock, has his brain removed for one that's alive and has eyes, thus giving them another "vehicle" to move around among the humans. It's conspiracy theorists' dream.

Harmony Shoal's scheme was five years in the making, so even after being defeated thanks to the combination of the Doctor and resident superhero, the Ghost, they weren't just going to scarper like the Atraxi, with Mr Brock warning the Doctor:

"The vengeance of Harmony Shoal is known and feared throughout the five star systems!"

Along with Brock, the only surviving member managed to escape UNIT's raid at its HQ by moving from Dr Sim's head into one of the soldiers. So they could be controlling some part of the Whoniverse out there.

Honestly, it's annoying constantly wiping away this blue gunk that keeps leaking from the nose and eyes.