The Barri were semi-sentient beings native to an unnamed planet in Wild Space. They were enigmatic space-faring creatures that could hitch rides on asteroids and derelict spacecraft for thousands of years in space. Their acid secretions broke down and helped them digest the asteroid they clung to.
Behind the scenes
Though the entry in Creatures of the Galaxy claims that the Barri are only 5 meters in length, the picture accompanying the entry shows two figures watching a Barri pass by, and are dwarfed by the immense size of the creature.