Raxacoricofallapatorian The Raxacoricofallapatorians were a race from the planet Raxacoricofallapatorius . Biology . External features . Raxacoricofallapatorians were large , bulky humanoid s . They had large eye s and powerful arm s with long claw s . They had thick , lumpy skin , ranging in colour from a yellow ish green , ( TV : " Aliens of London " / " World War Three " ) a paler , grey - green , ( PROSE : " The Monsters Inside " ) a much darker shade of green , ( TV : " The Nightmare Man " ) or a brown ish orange . ( TV : " The Gift " ) Raxacoricofallapatorians hatched from large , green egg s with several tendrils . ( TV : " Boom Town " ) By the age of twelve , Raxacoricofallapatorians were still considered children and were shorter than a human of equivalent age . ( TV : " Revenge of the Slitheen " ) As Raxacoricofallapatorians aged , they lost moisture from their tissue , calcifying and effectively turning into stone . ( PROSE : " The Slitheen Excursion " ) Despite their large bulk , they were also capable of surprising speeds and could easily overpower a human . Raxacoricofallapatorians could hunt by scent and could identify an individual ' s species , age , sex , emotional state and location by it . This sense of smell was officially the best in the galaxy . ( TV : " Revenge of the Slitheen " ) They could also sense the pain of closely related individuals from far away . ( TV : " Aliens of London " / " World War Three " ) Internal anatomy . Raxacoricofallapatorians were largely calcium - based life forms , ( TV : " Aliens of London " ) although in one account they were described as silicon - based . ( PROSE : " The Slitheen Excursion " ) Despite this , when posing as humans , they were able to eat carbon - based food , with some even enjoying it . ( TV : " The Gift " ) Due to their biochemistry , Raxacoricofallapatorians were vulnerable to acetic acid and would react explosively to it ( TV : " Aliens of London " ) , a feature that was utilised in the Raxacoricofallapatorian death penalty . ( TV : " Boom Town " ) Raxacoricofallapatorians had a more efficient metabolism than 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 acid ic . ( PROSE : " The Monsters Inside " ) The females of the species could create poison when in danger , released either by a dart - like claw or through their breath . ( TV : " Boom Town " ) This breath could render a human unconscious . ( COMIC : " Doctormania " ) Raxacoricofallapatorians lived in the chalky hills and the tall tree forests of Raxacoricofallapatorius . They froze and calcified on ice planets . ( GAME : " Plant and Animal Habitats " ) There also were at least two oceans on the planet , in which the Raxacoricofallapatorians swam . ( WC : " " ) Technology . The Slitheen and other criminals from the same race were scavengers , known for stealing advanced technology from other species . ( TV : " Revenge of the Slitheen " ) They were more advanced than human s and had developed faster - than - light travel in the form of slipstream engine s sometime prior to 2006 . They could also modify a pig into a humanoid form using their own technology . ( TV : " Aliens of London " / " World War Three " ) They also had small , hand - held teleportation devices , though they tended to have limited range and capabilities . ( TV : " Boom Town " , TV : " The Gift " ) Some of the Raxacoricofallapatorian technology appeared organic in nature . While in Justicia , Ecktosa and Dram used sticky nets as hammocks . These nettings were covered in a slime that quickly hardened away from body heat . Other Raxacoricofallapatorian buildings had their floors covered in a sticky substance . ( PROSE : " The Monsters Inside " ) In the 347th century , the Raxacoricofallapatorians also had molecular repurposing devices . ( PROSE : " The Slitheen Excursion " ) The Raxacoricofallapatorians ' most distinguishable technology was their compression field s . The Slitheen ( TV : " Aliens of London " / " World War Three " ) and Blathereen families ( PROSE : " The Monsters Inside " ) were able to disguise themselves as other , smaller humanoid s by fitting into their skins . This was done with the compression - field collars that they wore on their necks . When unzipped , pent - up energy was released through the zip in the form of a flickering blue light . Their size was controlled by the movement of gas , which caused a condition similar to farting , but with a smell slightly similar to that of bad breath due to calcium decay . ( TV : " Aliens of London " / " World War Three " ) These individuals originally needed to be large , but the advancement of technology meant smaller skins could be used . ( TV : " The Lost Boy " , PROSE : " The Monsters Inside " ) These skin suits were apparently inferior to those of other species . ( PROSE : " The Nightmare of Black Island " ) The Raxacoricofallapatorians mastered the concept of . ( TV : " Revenge of the Slitheen " ) Culture . Raxacoricofallapatorian society was based off families , such as those of the Slitheen , Blathereen , Slavereen , Caizeen , Lilieen , Rackateen , Chippeen , Fittereen , Hanazeen , Glizeen , Hostrozeen and Arlene . Raxacoricofallapatorian names were complex with the various hyphenation showing their exact placement on the family lines . ( WC : " " ) There were also mixed families , such as the Slitheen - Blathereen family ( TV : " The Gift " ) or the Hanazeen - Blathereen family ( PROSE : " A Comedy of Terrors " ) . According to Bloorm Vungah Bart Slitheen , the bartleboigle tree was used to discipline children , by spanking their backside s . ( TV : " The Lost Boy " ) Raxacoricofallapatorians were led by a Grand Council and an Assembly . ( TV : " Revenge of the Slitheen " ) The leader of this Council was the Lord Predator . ( PROSE : " The Slitheen Excursion " ) Unlike the Slitheen and Blathereen families most Raxacoricofallapatorians were a peaceful race that taught their children maths and poetry . they made their home world a paradise for them and other peace loving species and some of them were brilliant farmers but they despise criminal members of their species and punish them without mercy . The Raxacoricofallapatorians had the death sentence for dangerous criminals like the Slitheens , which was carried out in a gruesome way . The criminal would be 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 . ( TV : " Boom Town " ) Based on the comments of Blon , Raxacoricofallapatorians neither brushed their teeth nor prepared their food in complicated ways . ( TV : " 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 . ( PROSE : " The Monsters Inside " ) History . In 1903 , after receiving a wealth of information from the future , Grigori Rasputin saw people made of calcium . ( AUDIO : " The Wanderer " ) Raxacoricofallapatorians were part of the four - world Raxas Alliance along with the Abzorbalovian s and the people of Raxacoricovarlonpatorius and Clix . ( TV : " The Gift " ) Sometime before the 21st century the criminal Slitheen family bribed their way into power on Raxacoricofallapatorius . Their rule crashed the planet ' s economy and eventually the population rose up against them . ( TV : " The Gift " ) Exposed , shamed , and arrested in the , the entire family was tried and found guilty with no chance of appeal and given the death sentence . Many of the Slitheen fled justice , but the family continued to be hunted down by the Blathereen family and Judoon . The actions of the Slitheen ruined the good name of the Raxacoricofallapatorians . ( TV : " Revenge of the Slitheen " ) The Slitheen family preyed on other planets , especially Earth for many centuries . In the 347th century , Raxacoricofallapatorians ( possibly just the Slitheen ) fought in the Platonic War , alongside various other alien races , against the human race . In the year 34 , 600 , the Lord Predator was Haralto Wong Bopz Wim - Waldon Arlene . However he died shortly after this . ( PROSE : " The Slitheen Excursion " ) Alternate timeline . In an alternate timeline the Cybermen , using Borg technology conquered Raxacoricofallapatorius and converted the entire populace into Cybermen . ( COMIC : " Assimilation² " ) In a timeline created by a continuity bomb where the Doctor embraced the title of " Time Lord Victorious " and became a mad tyrant who ruled over time and space , a Raxacoricofallapatorian shot him dead without regeneration . ( COMIC : " Four Doctors " ) Minor references . Rose Tyler remarked the Abzorbaloff was " a bit Slitheen " , but when the Doctor asked he revealed that he was from Clom , Raxacoricofallapatorius ' twin planet . The Abzorbaloff spoke of the Raxacoricofallapatorians with contempt . ( TV : " Love & Monsters " ) The Tenth Doctor , having assumed the identity of John Smith , drew a picture of the Slitheen in " A Journal of Impossible Things " . ( TV : " Human Nature " ) A Raxacoricofallapatorian was seen at the Zaggit Zagoo bar where the Tenth Doctor went to visit Jack Harkness one last time before his regeneration . ( TV : " The End of Time " ) In 1903 , after receiving a wealth of information from the future , Grigori Rasputin foresaw , among other things , creatures made of calcium . ( AUDIO : " The Wanderer " ) Behind the scenes . " The Visual Dictionary " . The source " " gave further information about Raxacoricofallapatorian biology and culture . It said they were well adapted to their home - planet , with large eyes to see through the blizzards of the poles and powerful arms to swim through the oceans and to hatch from their eggs . While hunting , they would use their strength and poison - tipped claws to kill their prey .