Raxacoricofallapatorian



The Raxacoricofallapatorians are a race of large, calcium based aliens who have faced off with the Tenth Doctor several times.

Appearance and Biology
Raxacoricofallapatorians are roughly humanoid aliens with baby-like faces, a long neck and green skin. They have long arm with three sharp claws. They hatch from large green eggs with strange tendrils. Raxacoricofallapatorians are predators by nature and are excellent trackers. The females of the species can create poison as a last resort, which can be released by a dart-like claw or by their breath. According to The Monsters Inside, they also have a more efficient metabolism. They are nearly 3 metres tall and are much stronger then a human.

Due to their calcium based nature, Raxacoricofallapatorians are vulnerable to acetic acid and react explosively with it. One of the Raxacoricofallapatorian methods of execution is the lowering of the criminal into a cauldron of acetic acid, which is then heated to boiling. The acidity of the solution is formulated to dissolve the skin, allowing the internal organs to drop into the liquid while the condemned is still alive, resulting in a slow and painful death.

Technology
The Raxacoricofallapatorians are more advanced then humans, and have developed space travel by 2006.

The Raxacoricofallapatorians’ most distinguishable technology is their compression field. The Slitheen in the series are able to disguise themselves as other, smaller humanoids by fitting into the skins of the other aliens. This is done with the compression field collars that they wear on their necks. They need to inhabit larger creatures, since the compression fields have limited power (though by The Monsters Inside, the technology had been improved dramatically). Their size is also controlled by the movement of gas, which causes a condition like flatulence, but with a rotten tooth smell.

Television episodes

 * Aliens of London
 * World War Three
 * Boom Town
 * Attack of the Graske
 * (A stuffed Slitheen arm was also seen in Dalek)

Novels

 * The Monsters Inside