C is for... Clowns

For figures who represent fun, clowns have often been seen as creepy, scary characters. Many of the clowns encountered by the Doctor and his companions over the years have been threatening figures.
When trapped in the Celestial Toyroom, Steven and Dodo were forced to play a number of games in order to win back the TARDIS. The first of these was a version of Blind Man's Bluff against a pair of clowns - a male one named Joey, and a female named Clara. Joey never spoke, using a horn to communicate, but Clara could talk. They attempted to win the game by cheating, but the Doctor's companions won, and Joey and Clara were turned into lifeless dolls.

The Doctor's next encounter with clowns was, appropriately enough, at a circus. This belonged to a man named Luigi Rossini (real name Hugh Ross), but it had been taken over by the Master. Through Rossini, he turned the circus performers against the Doctor and Jo - prompting them to attack them. They were rescued by the appearance of the police - though these turned out to be disguised Autons.

On both of his encounters with the Mara, the Fifth Doctor came across more benign trickster / jester characters, whose humour was designed to counteract the evil of the Mara. A jester was also present at the castle of Sir Ranulf Fitzwilliam when he hosted King John.

When the TARDIS passed close to the planet Segonax, it was infiltrated by an advertising robot which was promoting the Psychic Circus. Ace revealed that she had a phobia about clowns, but the Doctor encouraged her to confront her fear. The clowns of the Psychic Circus were actually androids, built and maintained by a man named Bellboy. They were controlled by the human Chief Clown, who was a sadistic individual who had fallen under the malign influence of the Gods of Ragnarok, who demanded constant entertainment. Bellboy programmed the clown robots to kill himself. The Chief Clown was killed by another of Bellboy's robots, which also destroyed a number of the robot clowns.

When the Doctor, Amy and Rory became trapped in a spacecraft which was disguised as a 1970's hotel, they found that within each room was something which someone feared. This prompted the victim to fall back on their faith, upon which a Minotaur creature fed. One of the rooms contained a sad-faced clown, though it wasn't intended for any of the Doctor's party.

Sarah Jane Smith also had a phobia about clowns. A psychic entity contained in a meteorite fragment could manifest itself as something people feared. It took on several human likenesses - including a clown named Bob. Bob began to abduct pupils from the school which Luke, Clyde and Rani attended. He was traced to a clown museum in the area. Sarah had to confront her fear. Clyde was able to combat Bob with humour, as the entity could only feed on fear. Sarah then sealed the meteorite fragment in a box from which even thoughts could not escape.

Played by: Campbell Singer (Joey), Carmen Silvera (Clara), Bradley Walsh (Bob), Ian Reddington (Chief Clown), Lee Cornes (Kinda trickster).
Appearances: The Celestial Toymaker (1966), Terror of the Autons (1971), Kinda (1982), Snakedance (1983), The King's Demons (1983), The Greatest Show in the Galaxy (1988), The God Complex (2011), SJA 2.2 Day of the Clown (2008).

• Coulrophobia is the fear of clowns. 
• Bizarrely, Sarah found a photo of Clara from The Celestial Toymaker when searching the internet. Then again, UNIT had a photograph of her that was apparently taken on Peladon.
• There has been a recent epidemic of "killer clown" sightings across Europe and the US in the last year. This was expected to peak again with the cinema release of Stephen King's It.