The Galub slug was an ocean-dwelling parasite native to the planet Spira. Capable of reaching a length of two meters, Galub slugs had the ability to adhere to any solid surface using a powerful form of suction. They did this to attach to large sea animals in order to suck their blood. Non-sentient, they were also unintelligent and would mistake the hulls of boats for large sea animals and attach themselves to the unsuspecting passerby. The Galub slug possessed a thick, grub-white hide which was strong enough to deflect spears, but not blaster fire.
During the Galactic Civil War, a group of Alliance to Restore the Republic agents were participating in the 345th annual Spira Regatta Open when a sea slug attached itself to their yacht, slowing them. The Rebels were forced to use their blasters to free their vessel.