- "Hssiss are semi-intelligent beasts, corrupted and strengthened by prolonged exposure to the dark side. As creatures of the Force, they have a limited ability to mask their presence. Hssiss are drawn to suffering and carnage. They must have fed on all the corpses left over from the war here on Korriban. The angry phantoms of the Sith, too weak to influence the sentient, have taken these Hssiss as thralls to their will."
- ―Kreia, to Meetra Surik
Hssiss, or dark side dragons, were a lizard species with the ability to influence Force-sensitive beings around them. If bitten by a Hssiss, one would succumb to the effects of a dark side poison. Hssiss also had the ability to conceal themselves and become invisible, possibly doing so through the Force. Hssiss originated as savage reptilian predators on Ambria, and were one of the few creatures to survive the planet's destruction. They lived in and near Lake Natth, where Jedi Master Thon had imprisoned the dark side energies that had plagued the planet for millennia. The dark spirits then began to possess the creatures, turning them into something much fouler—it was said that these "dark side dragons" aided those who used the dark side of the Force. Eventually, Great Bogga began to use them as body guards and pitted them against those who had failed him. When he realized how effective and vicious they were, he had them transported off-world and sold in bulk. Soon, Hssiss could be found all over the galaxy, especially on worlds where the dark side was strong, including Korriban, Mimban and Vjun.
In appearance, Hssiss looked nothing more than particularly vicious reptiles, about three meters in length, with a green, scaly hide. In addition to those three meters, they had a meter long tail, covered in rows of spikes which stretched up past their backs and onto their necks. When in the lakes on Ambria, they hunted in pairs, grasping their prey with their strong jaws and sinking dozens of teeth into the unfortunate animal's body, while the other Hssiss sunk its jagged claws into it.
Dark Lizards were a species of hssiss.
- "Hssiss are enough to humble even an arrogant one such as you. Test yourself if you must, but try not to die."
- ―Kreia, to Meetra Surik
As creatures of the Force, they had a limited ability to mask their presence. Hssiss were drawn to suffering and carnage. After the Jedi Civil War and the devastation of the planet Korriban, they fed upon all the corpses left behind from the war, while the angry phantoms of the Sith—too weak to influence the sentient—took these Hssiss as thralls to their will, fending off all intruders who landed on the planet.
They were found on many planets throughout the galaxy, including Korriban, Ambria, Mimban and Vjun. Their prevalence was probably the result of being brought with Sith armies in their many wars. Many scientists believed the Hssiss originated from the planet Stenness.
The Jedi philosopher Tionne Solusar once met with a Hssiss on the planet Ambria. She killed it by removing its head with her lightsaber, but did not escape unscathed. The Hssiss had slashed her with its claws, and only a Jedi healing trance proved able to remove the venom. This led her to believe that the poison was spawned from the dark side of the Force.
Behind the scenes
In Star Wars: Knights of the Old Republic II: The Sith Lords, Ludo Kressh's tomb on Korriban contains an infinite hssiss spawn next to a dead Jedi. By looting the body, two Hssiss spawn. This is the basic level up glitch.
Strangely, when using Force vision to see the Force alignment, Hssiss are colored blue for a light-sider rather than red for a dark-sider.
- Star Wars: Tales of the Jedi — The Saga of Nomi Sunrider
- Tales of the Jedi (audio)
- Tales of the Jedi – The Sith War 4
- Star Wars: Knights of the Old Republic II: The Sith Lords
- Star Wars: The Old Republic Cartel Market
- Star Wars: The Old Republic: Rise of the Hutt Cartel
- Star Wars: The Old Republic: Galactic Strongholds
- Darth Bane: Rule of Two (Mentioned only)
- Darth Bane: Rule of Two audiobook (Mentioned only)
- Echoes of the Jedi
- Splinter of the Mind's Eye (First appearance) (Retcon)
- Splinter of the Mind's Eye 4 (Retcon)
- Fate of the Jedi: Ascension (Mentioned only)
- Fate of the Jedi: Ascension audiobook (Mentioned only)
- "Straight from the Horse's Mouth: A Guide to the Star Wars: Tales of the Jedi Universe, Part 2"—Star Wars Insider 27
- Tales of the Jedi Companion
- "ComicScan: Comics' White Knight"—Star Wars Galaxy Magazine 5 (Picture only)
- Star Wars Encyclopedia
- The Essential Guide to Planets and Moons
- The Dark Side Sourcebook
- The New Essential Chronology
- The Essential Guide to Alien Species
- The Official Star Wars Fact File 117 (German Edition - YUZ2, Yuzzem - Hin und Kee)
- The Official Star Wars Fact File 140 (HUT15, The Hutts)
- The Complete Star Wars Encyclopedia
- Jedi Academy Training Manual
- Book of Sith: Secrets from the Dark Side
- Star Wars: The Old Republic Encyclopedia
- Star Wars: Edge of the Empire Core Rulebook (Picture only)