Raxacoricofallapatorian

The Raxacoricofallapatorians were a race from the planet Raxacoricofallapatorius. Many Raxacoriocofallapatorian families were composed entirely of criminals, such as the Slitheen and Blathereen families.

Biology
Raxacoricofallapatorians were large, bulky humanoids, around 3 metres tall. They had thick, lumpy skin, ranging in colour from a yellowish green to a paler, grey-green (NDA: The Monsters Inside). They had the instincts of a hunter and long arms with three sharp claws which they use to kill their prey. Despite their large bulk, they were also capable of surprising speeds and can easily overpower a Human. Raxacoricofallapatorians could hunt by scent and can identify and individual's species, age, sex, emotional state and location by it. They could also sense the pain of closely related individuals from far away. (DW: Aliens of London, World War Three, SJA: Revenge of the Slitheen)


 * This ability to sense the pain of other individuals may have been telepathic, since it was shown to work from across planets. (NDA: The Monsters Inside)

Raxacoricofallapatorians hatched from large green eggs with several tendrils. The females of the species could create poison when in danger, released either by a dart-like claw or by their breath. (DW: Boom Town) Raxacoricofallapatorians had a more efficient metabolism then a Human, meaning they only needed to eat every few weeks and produced less waste. Raxacoricofallapatorian blood was red and their tears were milky in colour and slightly acidic. (NDA: The Monsters Inside) Due to their calcium-based biochemistry, Raxacoricofallapatorians were vulnerable to acetic acid and would react explosively with it (DW: Aliens of London), a feature that was utilised in the Raxacoricofallapatorian death penalty. (DW: Boom Town)


 * Humans and most near-humans had a carbon-based biochemistry.



Technology
The Raxacoricofallapatorians were more advanced then Humans and had developed faster-than-light travel in the form of slipstream engines sometime prior to 2006. They could also modify a pig into a humanoid form using their own technology. (DW: Aliens of London). Some of the Raxacoricofallapatorian technology appeared organic in nature. While in Justicia, Ecktosa and Dram used sticky nets as hammocks. This nettings were covered in a slime that quickly hardened away from body heat. Other Raxacoricofallapatorian buildings had their floors covered in a sticky substance. (NDA: The Monsters Inside)

The Raxacoricofallapatorians' most distinguishable technology was their compression field. The Slitheen and Blathereen families were able to disguise themselves as other, smaller humanoids by fitting into their skins. This was done with the compression-field collars that they wore on their necks. Their size was controlled by the movement of gas, which caused a condition similar to flatulence, but with a smell slightly similar to that of rotten teeth (due to their calcium-based biology) (DW: Aliens of London, World War Three). These individuals originally needed to be large, but the advancement of technology meant smaller skins could be used. (NDA: The Monsters Inside)

Culture
The Raxacoricofallapatorians had the death sentence for dangerous criminals like the Slitheens, which was carried out in a gruesome way. The criminal would lowered into a cauldron of acetic acid, which would then be heated to boiling. The acidity of the solution was formulated to dissolve the skin, allowing the internal organs to drop into the liquid while the condemned was still alive, resulting in a slow and painful death. (DW: Boom Town)

Based on the comments of Blon, Raxacoricofallapatorians neither brushed their teeth nor prepared their food in complicated ways. (DW: Boom Town)

Two known Raxacoricofallapatorians insults were "May plaque brown your belly" and "May your mother boil in the cauldron of atonement". Both were presumably related to their calcium based biology. (NDA: The Monsters Inside)

Minor references

 * The severed arm of a Raxacoricofallapatorian found its way into Henry van Statten's private museum of alien artefacts. (DW: Dalek)


 * The arm may have come from off the body of a dead member of the family Slitheen.


 * While attempting to bluff the Sycorax leader out of attacking Earth, Rose namedropped the Raxacoricofallapatorians. (DW: The Christmas Invasion)


 * Rose Tyler remarked the Abzorbaloff as "a bit Slitheen", but when the Doctor asked he revealed that he was from Clom, Raxacoricofallapatorius's twin planet. The Abzorbaloff spoke of the Raxacoricofallapatorians with contempt. (DW: Love & Monsters)