Not technically a species, droids are as different from living creatures as twi'leks are from jawas. From repairing blasters to repairing capital starships, from hacking imperial supercomputers to spying on rebel blockade runners, droids do it all.
The Ewoks are sentient furred bipeds native to the moon of Endor. They are curious individuals that stand about one meter tall. Although extremely skilled in forest survival and the construction of primitive technology like gliders and catapults, the Ewoks have yet to progress past stone-level technology. They are quick learners, however, when exposed to advanced technology with simple mechanical processes and concepts. (Bio borrowed from the Star Wars Databank)
The Gungans are the native inhabitants of the planet Naboo. They are an amphibious species with hardy lungs capable of holding breath for extended periods. As such, Gungans are as comfortable in water as they are on land.
While there are a number of different races, most Gungans exhibit the same physical traits. They tend to be tall and lanky humanoids.Their skeletal structure is extremely flexible, as it is made of cartilaginous material rather than hard bone. This makes their faces rather expressive, and makes their bodies more resistant to damage.
Gungans have strong leg muscles for swimming, and are aided by their long fin-like ears. Gungan arms end in four-fingered hands, and their feet have three stubby toes each. There isn't much visible physical difference between female and male Gungans. Females tend to be slightly smaller, with sleeker faces. They often tie their long ears back. (Bio borrowed from the Star Wars Databank)
Though not entirely different from the earthbound humans they're based off of, humans constitute the bulwarks of the galaxy. Although other societies are more unique and cultured, humans are the majority of the galaxy, and thus their lack uniqueness is undershadowed by their abundance.
The Hutts are rotund gastropods with their pudgy fingers deep in the criminal activities throughout the galaxy. They are so influential that they control the commerce on entire worlds scattered throughout the Outer Rim and elsewhere. One prominent member of this loathsome species was Jabba the Hutt, who operated from a dank palace on Tatooine. Hutts are about three meters long and have thick, oily skin. Two short, stunted arms protrude from their upper bodies. They have wide mouths and small yellow or red eyes. (Bio borrowed from the Star Wars Databank)
Maker defend the droid that has wandered away from its masters on the desert world of Tatooine. Of the many dangers that travel the dunes and crags of the arid world, few can send a droid's behavioral matrix circuitry into a tizzy like the Jawas.
They are hardly monstrous, appearing as meter-tall humanoids completely hidden behind rough, hand-woven robes. Their faces are concealed within the dark folds of a cowl, from which peer their sickly glowing yellow eyes.
The Jawas are a scavenger species. They comb the deserts of Tatooine in search of discarded scrap and wayward mechanicals. Using their cobbled-together weaponry, they can incapacitate droids and drag them to their treaded fortress-homes, immense sand-scarred vehicles known as sandcrawlers. (Bio borrowed from the Star Wars Databank)
The Mon Calamari are said to be the soul of the Rebel Alliance. The Empire pressed these gentle, amphibious people into war by subjugating their watery world. In retaliation, the Mon Calamari became one of the key species of the Rebellion, supplying badly needed warships to the outnumbered Alliance fleet.
The Mon Calamari people are humanoid, about 1.7 meters tall. They have salmon-colored skin, high-domed heads, webbed hands and large, goggle-like eyes. (Bio borrowed from the Star Wars Databank)
Fearsome desert savages inhabiting the rocky Jundland Wastes, Tusken Raiders are the foremost reason Tatooine colonists do not wander far from their isolated communities. Extremely territorial and xenophobic, Tusken Raiders will attack with very little provocation. They show no allegiance to even their native world-mates, as these nomads have attacked Jawa scouting parties on occasion. They have even gathered numbers large enough to attack the outskirts of smaller towns like Anchorhead.
Covered from head-to-foot in tattered rags and robes, Tusken Raiders -- or Sand People as they are also known -- brandish a deadly bladed club known as a gaderffii. They also carry projectile rifles with which to shoot at passing vehicles. The male of the species tend to be the aggressors. Females can be distinguished by their elaborate jeweled masks with eyeslits and torso-covering sand-shrouds. Tusken children wear unisex cowls and simple cloaks. (Bio borrowed from the Star Wars Databank)
Few things are as graceful as a female Twi'lek in motion. This beautiful image has forever doomed generations of young Twi'leks into servitude, as the wealthy and corrupt have taken to brandishing Twi'leks as badges of prestige.
Twi'leks are tall, thin humanoids with skin pigment that spans a rainbow of colors. Their most distinctive feature is a pair of shapely prehensile tentacles that grow from the base of their skulls. (Bio borrowed from the Star Wars Databank)
Shaggy giants from an arboreal world, the tall and commanding Wookiee species is an impressive sight to even the most jaded spacer. Despite their fearsome and savage countenance, Wookiees are intelligent, sophisticated, loyal and trusting. Loyalty and bravery are near-sacred tenets in Wookiee society. When peaceful, Wookiees are tender and gentle. Their tempers, however, are short; when angered, Wookiees can fly into a berserker rage and will not stop until the object of their distemper is sufficiently destroyed. (Bio borrowed from the Star Wars Databank)