Tynaker
Tynakers were a species that stole information to sell for minerals, destroying civilisations in the process. They lived outside the usual timelines.
Biology
Tynakers had ruby, multi-faceted eyes. They had four arms and four finger-less hands. They were grey in colour. Their bodies were amorphous and could morph into feet when necessary. They had razor-sharp teeth. (PROSE: Losing Track of Time)
History
At some point, the Time Lords had stopped the Tynakers from stealing information from other planets. However, a group of Tynakers made their way to Earth, where they proceeded to steal books, and therefore knowledge, from the Bodleian library. They were defeated by the Third Doctor and Jo Grant when the Doctor destroyed their temporal device. (PROSE: Losing Track of Time)