From Holocron - Star Wars Combine
|Average Height||1 to 1.8 meters |
|Skin color||Gray, pink, or light green |
|Distinctions||Large ears, scarns, ultra-sensitive hearing, jet-black eyes, naturally tucked in cheeks |
|Known Members||List of known Sullustans|
Biology and appearance
The Sullustan are a race of small, mouse-like humanoids can be distinguished by their huge almond-shaped black eyes, loose jowls called "dewflaps", and large, round ears. Their skin colour is usually pink, but some are grey or light green. They salivate quite often and live underground to avoid Sullust's inhospitable atmosphere. Their ingenuity and adaptability have allowed them to create huge underground cities, and their technology has grown at an incredibly fast rate.
Humanoids, Sullustans can see up to 20 metres in the dark and have an incredible sense of direction, having lived in caves all their lives. Additionally they are known to have the uncanny ability to remember a path or map exactly, even after the first time they see it. Thus, many Sullustans have become pilots and navigators.
Unfortunately, due to the evolution of the species in a low-light or completely dark environment, they are genetically predisposed to corneal defects at around the age of 30 years or so; many choose to wear special visors to prevent further damage when this condition manifests itself.
Society and culture 
Sullustans are outgoing and mercantile, friendly and pragmatic. As a species they are altogether lacking in xenophobia. Though fond of practical jokes and extremely shrewd in their business dealings, they are eager to explore and travel the galaxy. Inquisitive by nature, some have described Sullustans as reckless, especially for their preference to learn and discover whenever possible through personal experience.
Sullustans organize themselves into familial units known as Warren-clans. Each clan consists of one polyandrous female, several husbands and their young. Unmated females, known as "Fems", are active members of their communities until they reach the status of "Ready" which marked their breeding years. At the outset of Ready, "Fems" choose their mates and found their own Warren-clans.
Few Sullustans leave their homeworld, but those that do often find employment as pilots or merchants. Inspired by legends like Mayjeln, Sullustan spacers put their skills as navigators to use and are prized crewers across the galaxy. Because of this, their flowing, staccato language of Sullustese was known to many smugglers. Sullustan names are often direct translations from Sullustese words and typically consisted of a given name and surname of four letters each.
Burial rites are given particular focus in Sullustan culture, with vast crypts and vaults maintained by crypt masters. Death, known as "Eternal Sleep", is viewed with great reverence. The most important of these rites is the Tomb-walling Ceremony, an elaborate funeral procedure. Important leaders and famous Sullustans were entombed in the Gallery of Ancestors and the Catacomb of Eminents.
Sullustan religion appears to be polytheistic, including a pantheon of gods like Triakk.
Governmentally, Sullustan names referencing nobility is evidence of some form of monarchy, but all recorded history demonstrates the use of democracy.
Sullustans are also dedicated to the principles of capitalism and open markets, but were primarily motivated by the possibility of bettering their people, not greed. Sullust's technologically advanced underground cities bristled with shops and markets attractive to tourists from across the galaxy.
Oddly enough, Sullustans eventually replaced Wookiees as the galactic experts of the hairstyling business—in spite of the fact that they were almost devoid of hair. The Barbers of Sullust were renowned for their skill with the cosmetic arts.
References:  - http://starwars.wikia.com/wiki/Sullustan