Granite Slugs are a species of gray-green silica parasite indigenous to the planet Coruscant. They superficially resemble small terrestrial mollusks. To travel, they leave behind a slime trail consisting of corrosive acid. They also possess four eye stalks, two mouths, one muscled foot, lung filaments, and suction pseudopods.
Granite Slugs have evolved from an ancestor which was imported to the planet Coruscant in 340 BBY during an attempt by the Galactic Republic to clean up garbage that existed in the lower levels of the city.
The large amount of food materials in the area resulted in a rapid growth boom in Granite Slug population; and while this resulting in increased 'cleanliness' throughout the city it also led to an increase in predator populations as well.