Brain slugs, alternatively called brain-slugs, represented a species of slugs whose origin was Nusa Sept V, their homeworld. Possessing both mouths and tongues, they were, however, devoid of eyes. The idiom "like stealing slime from a brain-slug" was a common way of expressing how simple something was.
The brain slugs received a mention in Tom Angleberger's young readers novel from 2015, Return of the Jedi: Beware the Power of the Dark Side! This novel was a reinterpretation of Star Wars: Episode VI Return of the Jedi.