Krillitane
Krillitanes are a race of aliens who could take physical features from races they conquered.
- This adaptability means that all information given is only applicable for the Krillitane seen in School Reunion. When The Doctor first met them they looked like Humans with very long necks. By the time of School Reunion they had a completely different form. This also means the Krillitane may have been seen before, but in a different form.
The Krillitanes are bat-like humanoids, though smaller then Humans. They had various shades of pinkish skin, sharp claws and a flattened, fanged face. They took their bat-like wings from the inhabitant of Bessan, and they also sleep upside down like bats and have very sensitive of hearing. As well as a bat-form, the Krillitanes can create a morphic illusion of a Human (which Mr Finch preferred). Krillitanes are carnivorous and will eat other sentient creatures, but they will also eat rats. They also produced Krillitane oil which can increase intelligence in humans but is currently deadly for Krillitanes. They are aware of the Time Lords and their extinction.
In 2007 they had taken over Deffry Vale School. Using the Krillitane oil and an advanced computer network, they were using the brains and imagination of the students as a type of computer in order to work out the Skasis Paradigm. (DW: School Reunion)