Space worm
From Wookieepedia, the Star Wars wiki.
Space worms were gigantic creatures, capable of surviving in space, which fed on minerals. They were responsible for hollowing out Eskaron, a moon in the Cularin system, but due to this they exposed Eskaron's molten core, which expanded, destroyed the atmosphere and killed some of the worms. When the worms used up their food source, they moved on from the system millennia before it was discovered by Reidi Artom.
The remnants of one worm was found in Eskaron and called simply the Worm.
The space worms might have been space slugs. If they were not, they were probably closely related.
