from their home planet Raxacoricofallapatorius and are tracked down by the Judoon and law abiding Raxacoricofallapatorians. They are large and very bulky in appearence. They have puppy like eyes and long arms with Claws. They can kill humans and use their bodies as disguises, by using high tech equipment attached to their necks it helps them fit into Human skins. feamale slithen are able to shoot a poisonous dart from there fingers.
The Slitheen first appear in the 2006 episode Aliens of London/World War Three.A large Mysterios spaceship crashes into the River Tems, after knocking a chunck out of big ben. Special forces are called in to recover what they can and a body is found. The body turns out to be a mere distraction set by the slitheen so they can infriltrate pepole of importance in the London area, after killing the Prime Minister the Slitheen take a job at acting prime minister, Their ultimate plan was to ignite world war three and sell of chuncks of the Earth to other planets, however due to the Ninth Doctors intervention all but one of the Slitheen are killed when the Doctor blows up 10 downing street.
Not long after the remains of a Slitheen are recoverd by a rich American called Henry Van Satten who keeps it in his private alien museam. The last maijor Doctor Who appearnce for the Slitheen was in the episode Boom Town, in which the only surviveing Slitheen from the massacre in london is now mayor of Cardif in Wales and plans to open the Temporal Rift which would destroy the Earth,It planned to escape with a Spacesurf board, but just before her plans fall in to place she sees the hart of the Tardis and transforms back into an egg, the Doctor then takes it to Raxafalapoturios and leaves it on a farm to be raised propely. The Slitheen cameo in several episodes afterwards,one Slitheen is seen in the Christmas Special episode Attack of the Graske were one had been captured by the Graske. It is later indirectly relesed by the Doctor where it goes onto attack a group of Graske. Another Slitheen appears in a space bar alongside Hath, Adipose, Sycorax, Judoon and a whole host of other unidentified aliens.
Sarah Jane Adventures
The Slitheen appear often in the Sarah Jane Adventures. They are first seen Infaltrateing an ordiary school in London aswell as other schools across the world and again planned to destroy and sell Earth of in chuncks, but the intervention of Sarah Jane her newly adopted son Luke and his two freinds, The Slitheen mostly flee however some are killed.
The Slitheen return led by the son of one of the Slitheen killed by Sarah jane in their previous encounter, and posed as Luke's real parents and planned to kill him as an act of revenge, but they are again beaten by Sarah Jane and they flee the Earth.
A single Slitheen is breifly seen in the begining of the episode The Gift, but it is quickly killed by a pair of Blathereen.
- There are several toys of the Slitheen.
- The slitheen alongside the Bane are the main villains in the Sarah Jane Series.