Teuthoidian

The Teuthoidians are a sapient species of slug-like creatures and one of the first spacefaring civilizations to evolve in the universe.

Biology
Teuthoidians are large slug-like beings which leave trails of colloidal secretions (i.e. slime) as they move. They are hermaphroditic and known to practice cannibalism.

Culture and society
The interior of their spaceships is covered in colloidal secretions to facilitate the Teuthonians' locomotion. They evolved in one of the earliest eras of the universe and were one of the first spacefaring species to exist. They never discovered time travel.

Appearances

 * Big Finish Doctor Who audio stories, The Chaos Pool (2009)