Twi'leks, sometimes referred to disparagingly as "Tail-heads", were an omnivorous humanoid species originating from the planet Ryloth. They tended to eat cultivated molds, fungi, and rycrit meat. Their distinctive features included colorful skin, which varied in pigment from individual to individual, and a pair of shapely prehensile tentacles that grew from the base of their skulls. The tentacles, called "brain-tails", "lekku", "tchun-tchin", or "head-tails" were advanced organs used for communication and cognitive functions. Twi'leks possessed a fairly standard humanoid vocal structure and were capable of learning most alien languages; however, they usually preferred their native language of Ryl, which incorporated subtle movement of the lekku. When they wished, they could even communicate in complete secrecy using their versatile brain-tails. Twi'lek females were often used as slaves or dancers because of their beauty.
The Twi'leks were a sentient species of mostly hairless mammals. They were humanoid in form, with two legs and two arms.
Males had humanoid ears, and among females there was equal biological evidence for humanoid ears and ear "cones". While some headdresses were cultural decoration to denote status, quite a few were originally introduced as "muzzles" to prevent the slaves from having access to a language that non-Twi'lek handlers could not understand.
Both males and females have little to no body hair, with the only notable exception being eyelashes to aid in keeping out the sand and heat of Ryloth. Females typically had painted eyebrows or had their eyebrows tattooed on, in order to appear more palatable and less alien to more base-line humanoid offworlders. Boc Aseca had body hair under the armpits and on his chest, though it is unknown whether this was the result of some genetic mutation, a rare subspecies, or something else
Female Twi'leks have been considered especially attractive and slender, which made them favorite subjects for slavery and entertainment. The beauty of female Twi'leks was well known throughout the galaxy, and as a result many young Twi'leks were sold into slavery, becoming dancers or status symbols, most notably by Jabba Desilijic Tiure.
The Twi'leks were omnivores. This diet was essential given that food was scarce on their homeworld, Ryloth. Twi'leks possessed multiple stomachs, an unusual trait that enabled them to eat almost any food. When traveling off their homeworld, Twi'leks rarely refused food, which frequently led to obesity among starfarers. Twi'lek society also associated obesity as a sign of affluence and success. In the case of obese Twi'leks, ear flaps enlarged to store fat.
Although unsubstantiated, some in the New Republic speculated about a possible relation between the Yevetha and Twi'leks.
+2 to Dexterity, -2 to Wisdom, +4 to Charisma, Species Size is Medium, Racial Language is Ryl