Here's a look at some of the memorable Dr Who villains from the past 40 years.
Behind each Dalek lies a tragic story: the robotic assassins contained - and were controlled by - the mutilated remains of a Kaled, a once-noble race of teachers and philosophers caught in a nuclear war with their bitter rivals, the Thals, and thereafter dedicated to intergalactic despotism.
That was the plot line underpinning the introduction of the iconic Doctor Who baddies on December 21 1963 when the ambulating pepper pots armed with a sink plunger had their first of many encounters with the doctor.
The tin-voiced creatures, with their trademark "Exterminate!", were the invention of Doctor Who writer Terry Nation, but their appearance was left to Raymond Cusick, a designer in the BBC's special effects department who based his creation on a canteen cruet set. Built around a wooden frame with a dimpled metal casing and three castors to allow the actor seated inside to move it around, there were only three fully operable Daleks for each episode.
Cy Town, who played a Dalek for 15 years until the final encounter with their malign creator, Davros, in 1988, said: "All the other Daleks were just dummies with technicians lying on the floor poking them with sticks to make them move. They were tricky to manoeuvre; you had to push them along with your feet and your knees. And once you were locked inside, you had to be let out. Sometimes they forgot me and I was left for hours."
After hiding in the depths of Loch Ness following the destruction of their planet by solar flares, the Zygons launched their attempt to capture Earth in the 1975 episode Terror of the Zygons. Using a destructive pet predator, the Skarasen, the monstrous race destroys a Scottish village before setting their sights on Westminster. The Zygons, a cross between an Easter egg and the off-cuts of a rubber tubing factory, were like almost all other Doctor Who monsters created by the BBC's in-house props and visual effects department.
THE GIANT MAGGOTS
Fashioning the giant green maggots created by an intergalactic pollution incident for a 1973 episode demanded condoms. Faced with creating the effect of a maggot capable of eating two humans, the special effects department resorted to inflating the contraceptives and painting them green. Using trick photography and pots of goo, they were then made to look as if they were attacking the doctor and his sidekick.
Fortunately, the creatures, on the point of pupating into giant insects, are found to be susceptible to a type of poisonous fungus fashioned from foam rubber.
As the Cyberleader said to Tom Baker while he battled an evil plot to wipe out civilisation with cobalt bombs in 1975: "Cybermen can survive more efficiently than animal organisms. That is why we will rule the galaxy."
The silvery psychopaths from the planet Mondas, the twin of Earth from which the Cybermen were siphoning energy, made their first appearance in 1966.
The inhabitants of Mondas had been the victims of a terrible plague, and had to resort to substituting cybernetic limbs and organs to survive. As they lost the last vestiges of human flesh, they also lost their emotions.
This may or may not explain why the Cybermen's helmets, featuring a car lamp on a skull cap, were held together with sticky tape.
By 1988, the Cybermen, who were arguably second only to the Daleks in the longevity of their desire to bump off the Doctor, had assumed fully fitted rubber masks and green goo that squirted from their bodies when they were blown up.
When the Tardis arrived in Tibet in 1935, the Doctor, played by Patrick Troughton, encountered a horde of murderous Yetis. The creatures, more closely resembling a children's television character than a wild beast, turn out to be robots built by a nebulous alien which has taken over the body of the "High Lama" in a bid to conquer the world.
The Yetis corner the Doctor and his assistant at one point in the 1967 episode, leading to the following exchange:
Assistant: Have you thought up some clever plan, Doctor?
Doctor: Yes, I believe I have.
Assistant: What are you going to do?
Doctor: Bung a rock at it.
When the episode was turned into a book, the names of Tibetan characters, who had been real historical figures, were slightly altered to avoid giving offence.
One of the more conventional opponents faced by the Doctor was created for this 1971 episode when Jon Pertwee does battle with the Devil in an English village. The lack of any intergalactic ingredient, however, did nothing to quell the creative powers of the BBC's props department.
Asked to create Bok the Gargoyle, a petrified stone assassin reanimated by his satanic chief, Azal, the costumiers came up with a grey body suit, strap-on wings and a rubberised mask complete with rigid tongue. The character nonetheless had the ability, on the screen, to fly and change size.
Designed as terrifying giant ants, the Zarbis were among the first Doctor Who monsters, seen in the 1965 episode, The Web Planet. Unfortunately their ability to scare was reduced by the sound of one of the plastic and rubber monsters hitting a camera with an audible thump in one instalment and another clanging its abdomen on the studio floor.
When confronted by one of the creatures, the Doctor, played by William Hartnell, said: "Apart from rubbing our legs together like some sort of grasshopper, I doubt if we can get on speaking terms with them."
One of the most ludicrous evil geniuses, the Kandyman, was an inhabitant of the planet Terra Alpha, where sadness was against the law. Looking like a demonic product of congress between the Liquorice Allsort character Bertie Bassett and a beach ball, the character killed those who broke the law by dumping them in a stream of molten candy.
In Happiness Patrol, in 1988, the Kandyman explained: "You see, I make sweets. Not just any old sweets, but sweets that are so good, so delicious that sometimes, if I'm on form, the human physiology is not equipped to bear the pleasure."
The confectionery killer, fashioned from foam rubber and plastic tubing, was beset by technical problems.
By the third instalment, the costume department had had to fit their villain with a large metal mouth brace. It later transpired that it had been fitted because the actor playing the character could be seen moving inside the costume.