Arguably the most recognisable and notorious original monster of the new series of Doctor Who, the Slitheen are big green, bug-eyed aliens who made their debut in the first two-part story of Series One. They have the notable distinction of being the first monsters in Doctor Who to be realised through a combination of CGI and costume - CGI Slitheen for the running and action sequences, and performers in rubber suits for any other scene.

Characteristics

The Slitheen stand over seven feet tall with waxy green skin and strong, three-clawed hands that can easily lift a human. Other notable features include a beer belly and a rugby ball-shaped head with round, prominent eyes that blink horizontally, with the eyelids left and right rather than up and down. The female of the species can shoot a poison dart from her claw or, in situations of dire peril, exhale the excess poison through the lungs. Slitheen are calcium-based life forms that hatch from eggs, originating from the tongue twisting planet of Raxacoricofallapatorious. Their unusual calcium-based physiology makes them highly vulnerable to acids, even vinegar.

Family business?

Slitheen is not actually the name of their species – it is only the surname of this particular family. However, since no-one has actually thought up a better name for their species than Raxacoricofallapatorians, most Raxacoricofallapatorians prefer to be known by their family name. Other prominent families include the Blathereen¹ and the Rackateen.

The Slitheen are a family of criminals, exiled from their home planet and left to wander the stars. Should they ever return home, to Raxacoricofallapatorious, they will be put to death in the most excruciating way possible². They survive on the profits of various criminal heists, during the execution of which they have occasionally come into contact with that mysterious Time Lord, the Doctor.

Stories

WARNING – MAJOR SPOILERS FOLLOW

Aliens of London/World War Three

In this two-parter, the Slitheen land their spaceship in the North Sea and infiltrate the British government. They kill off several influential people ³ and turn their skins into suits, which they wear as a disguise. They fit their enormous frames into the smaller human form⁴ thanks to slipstream technology that compresses their bodies down⁵. Unfortunately, one side effect of this technological marvel is chronic flatulence, caused by a faulty gaseous exchange system. While farting in public is a social no-no on Earth, the Slitheen find it highly amusing.

The Slitheen then crash a spaceship into the Thames (causing significant damage to the tower of Big Ben on the way) and assassinate the British Prime Minister and much of his senior staff, leaving Slitheen duplicate Joseph Green as Acting Prime Minister. Playing on the worldwide panic caused by the crashed spaceship, Joseph Green declares an alien armada sits in wait above the planet about to destroy it. He begs the United Nations to give the United Kingdom nuclear release codes so they can destroy the aliens – but their real intent is to nuke every nation on Earth and trigger an all-out nuclear world war. Safe in their hidden spacecraft, the Slitheen intend to then sell off the radioactive remains of the Earth as cheap fuel for alien spaceships.

However, their plan is foiled when the Doctor and Mickey Smith manage to blow Downing Street up with a missile, by hacking into the UNIT⁶ computer network, destroying the Slitheen before they can launch the nuclear missiles.

Boom Town

One of the sisters of the Slitheen family, Blon Fel Fotch (also known as Margaret Blaine), managed to escape the destruction of Downing Street by an emergency teleport device. After a rocky start, when she rematerialised in a skip on the Isle of Dogs, Blon managed to get herself elected mayor of Cardiff, and organised the demolition of Cardiff Castle for the building of the Blaidd Drwg⁷ nuclear power station. Blon intended to have the station built on a time rift⁸ in the heart of Cardiff, which would result in the destruction of the planet upon activation of the facility. Blon planned to ride the waves of destruction to safety on her tribophysical macrokinetic waveform extrapolator (a sort of pan-dimensional surf board).

Once again, the Doctor shows up to foil her plans. This time though, he isn't quite as on top of things as he thinks – as Blon lures the Doctor away for a last meal, leaving her extrapolator to sap the power of the TARDIS to open the time rift. The Doctor uncovers Blon's duplicity and returns to the TARDIS to find it on the verge of breaking up - when the console breaks open, revealing the burning heart of the time machine, and regresses Blon to an egg. The Doctor fixes the problem at the last minute, and promises to give the regressed Blon a second chance – he’ll take her back to Raxacoricofallapatorious and give her to a better family who’ll bring her up properly this time.

The Monsters Inside

Stephen Cole's tie-in novelisation, set several centuries after the previous stories, finds the Blathereen family undercutting their Slitheen relatives in organised crime on human colonies out in the depths of space.

The Blathereen have taken over the penal planetary system of Justicia using new improved compression technology that allows them to fit inside the skins of thin people. Using the human prisoners (including Rose) as a workforce and the alien prisoners (including the Doctor and two Slitheen, Ecktosca and Dram) as scientists, they develop a fiendish plan to transport the entire Justicia solar system through wormholes in space, then roast entire planets by controlled solar flares before selling them off as rocket fuel⁹.

However, the Doctor and Rose soon realise the truth and fight back. Maggi Jalovitch (really Ecktosca and Dram's Aunt Callis come to rescue her nephews) starts a prison riot that results in the death of many Blathereen. In the final confrontation, the Blathereen Ermenshrew kills her half brother and family leader, Don Arco, for cowardice before trying to activate the wormholes. However, since the Slitheen and the Doctor have sabotaged the system, she succeeds only in blowing up her own mothership and killing herself with a power feedback from her console.

The human population take back control of Justicia and begin rooting out the Blathereen imposters. Some wrongly imprisoned felons are pardoned, and the Slitheen cheat death to return to a life of crime once again...

Miscellaneous

• A CGI Slitheen appears at the conclusion of the interactive adventure 'Attack of the Graske'
• A stuffed Slitheen arm is seen in Van Statten’s alien museum in the series one episode 'Dalek'.
• The Slitheen make a brief appearance in the Tenth Doctor novel Nightmare of Black Island by Mike Tucker, as one of the nightmare monsters hunting the Doctor.
• In the series two episode 'Love and Monsters' it is revealed that the Abzorbaloff is from Clom, the twin planet of Raxacoricofallapatorious.
• They have their own book in the Doctor Who Files series. The book tells us a few more facts about them before they feature in a short story called 'No Fun at the Fair'.
• They feature as the malevolent villains in the first episode of The Sarah Jane Adventures, 'Revenge of the Slitheen', disguised as teachers at a local school.

---

¹ Who played a prominent part in the BBC spin-off novel The Monsters Inside by Stephen Cole.
² More information on the back story of the Slitheen can be found in Justin Richards's book Monsters and Villains.
³ Namely Joseph Green, MP for Hartley Dale; Margaret Blaine, Head of MI5; Oliver Charles, Transport Liaison; General Asquith; Group Captain Tennant-James, RAF; Sylvia Dillane, Chairman of the North Sea Boating Club; Ewan McAllister, Deputy Secretary for the Scottish Parliament; and an unnamed police officer.
⁴ Though admittedly preferring the stouter members of the population.
⁵ The compression field control is a grey box worn around the Slitheen's neck.
⁶ The United Nations Intelligence Taskforce, for whom the Doctor has worked as scientific advisor since his third incarnation.
⁷ Welsh for 'Bad Wolf', a consistent reference found throughout Doctor WhoSeries 1 that ties in to the climactic conclusion.
⁸ Forced open by the Doctor in the episode 'Unquiet Dead' and located beneath the headquarters of Torchwood 3.
⁹ An update on the Slitheen plan from 'Aliens of London'.