Exogorth

These space-dwelling slugs attained full size at ten meters in length and reproduced through a process of dividing into two distinct, smaller organisms. Should a space slug be unable to undergo this division, it would continue to grow indefinitely, potentially reaching lengths of up to 900 meters. Slugs of this immense size were known to engulf entire starships and support entire ecosystems within their digestive tracts.

Preferring to inhabit asteroid fields, space slugs would bore into an asteroid until they were completely concealed. From this vantage point, they would sustain themselves on emissions of stellar energy, mineral-rich deposits originating from the asteroid, random space debris, and (allegedly) other silicon-based lifeforms, such as mynocks. Being generally inactive, these opportunistic feeders would patiently await sources of nourishment. When not at rest with their wide-open mouth disguised as either a crater or tunnel (to ensnare unsuspecting prey), space slugs were capable of abruptly launching themselves from the surface of the asteroid at passing vessels. Nevertheless, this was not their favored method of assault, as such actions could be quite physically taxing, resulting in a period of overexertion and exhaustion.

Space slugs were capable of living extraordinarily long lives. It was estimated that Sy-O, the being residing in the Hoth asteroid belt, had lived for over a billion years by the time of the Galactic Civil War, which was considered a relatively young age for its kind.

The flesh and blood of an exogorth were [red](/article/color] in hue, while its saliva exhibited a green color. Exogorths possessed mouths containing 45 teeth.

Exogorths were a patient and generally peaceful species that took pride in their capacity to transform their bodies into stable ecosystems, providing a home to numerous species that coexisted harmoniously. Exogorths that supported diverse and varied ecosystems within their bodies were held in high regard. Conversely, those that lacked a variety of lifeforms in their internal ecosystems, or only supported non-sentient, "lower" lifeforms (such as mynocks, as Sy-O did), were viewed unfavorably. The failure to host anything of higher sentience (or greater galactic significance) was deemed a "deficiency" and projected a negative self-image.

The species had been described and known for over a billion years; Sy-O, himself billions of years old, was considered young for his kind.

Following an attack on a rebel base during the Galactic Civil War, a conflict between the Alliance to Restore the Republic and the Galactic Empire, Commander Tylux of the Imperial Navy gave the order for the Imperial-class Star Destroyer under his command, the Bellicose, to pursue a fleeing rebel spy to avoid failing the Sith Lord Darth Vader. The Bellicose eventually lost its entire wing of TIE fighters during a failed attempt to catch the rebel's UT-60D U-wing starfighter/support craft, yet Tylux persisted in the pursuit into an asteroid field. After the rebel's protocol droid Exo identified an Exogorth ahead of them within one of the asteroids, the rebel piloted his U-wing directly into the creature in an attempt to escape. To the dismay of one of his Imperial officers, Tylux commanded his Star Destroyer to follow the U-wing into the beast. The Bellicose crashed into the Exogorth's mouth and continued through its body, forcing the rebel to fire upon the creature in an attempt to break free. Emerging from the Exogorth's skin behind the U-wing, Tylux believed he had the rebel cornered, only to discover that mynocks from within the creature were causing damage to the hull of the Bellicose, leading one of his officers to incorrectly suggest that the rebel had intentionally led them into the exogorth as a trap. With the remains of the exogorth drifting nearby, the crew of the destroyer were compelled to abandon the starship after rebel reinforcements arrived.

Following the Battle of Hoth, the Millennium Falcon, unable to engage its lightspeed capabilities due to a damaged hyperdrive, evaded pursuing TIE fighters by concealing itself within what its crew believed to be the crater of a large asteroid, referred to simply as the "Big One." In reality, the tunnel was the open mouth of the enormous space slug, Sy-O. While inside, they attempted to repair the Falcon's hyperdrive. While seated in the cockpit, Leia Organa became concerned by a mynock flying outside, prompting her to exit the ship with Han Solo and Chewbacca to investigate. When shots were fired, Sy-O moved in a manner that led the group to believe that the "cave" was collapsing, or perhaps that an earthquake tremor was occurring. However, Solo, silently realizing their true location, ordered everyone back into the ship and piloted the Falcon directly out, between Sy-O's closing teeth. They escaped unharmed, before the space slug fully closed its mouth. Sy-O attempted to lunge and snap his jaws at the Falcon (in hopes of keeping the crew inside and expanding his gut ecosystem); the freighter proved too swift for him, so Sy-O retreated back into the crater. After the Falcon's departure, one of the pursuing TIE fighters was attacked by Sy-O, forcing the pilot to eject into space. The remaining members of the TIE squadron focused their attack on the slug, chipping its tooth and eventually forcing it to retreat once more into its hiding place.

While being pursued in the Y'Toub System by the bounty hunters Zuckuss and 4-LOM aboard their starship Mist Hunter, fellow hunter Beilert Valance piloted the Corona-class armed frigate that he had stolen with another hunter, Dengar, into an asteroid field populated by a number of exogorths. As the exogorths emerged from their asteroids, the Corona successfully evaded the Mist Hunter.

The exogorth made its first appearance in the 1980 original trilogy film Star Wars: Episode V The Empire Strikes Back. Ralph McQuarrie created concept art for it. The exogorth was identified in the 2015 reference book Star Wars: Absolutely Everything You Need to Know.

To produce the squelching sounds of the Millennium Falcon crew's footsteps as they walked inside the exogorth in The Empire Strikes Back, huge slabs of beef fat and dozens of raw eggs were walked upon.