Na'vi

One of the challenges in designing Neytiri was making her look sufficiently alien and yet familiar and appealing enough to make Jake's attraction to her natural and convincing


In Avatar, the Na'vi are an indigenous species that live on Pandora. They are humanoid in appearance and are 9 to 10 feet (2.7 to 3.0 m) tall, having pairs of eyes, ears, arms, legs and feet like humans, as well as a nose, a mouth, and expressions recognizable to humans. The Na'vi differ from humans in having blue striped skin, pointed and mobile ears, large eyes, catlike noses and teeth, tails, and four fingers (hybrid avatars retain the five fingers of their human DNA). While taller than humans, they have narrower proportions in body frame. Their bones are reinforced with naturally occurring carbon fiber. The Na'vi also have a distinctive tendril feature protruding from the back of their heads, surrounded by hair (resembling a long braid or queue), feeding directly into the brain. This organ allows them to connect with other organisms around them, transferring electrochemical signals such as thoughts and memories to the trees, plants, and other creatures. In the original script, Cameron refers to these as "Jubilees" although the word is not used in the film and may be changed by the time the novel is published. The Na'vi were initially conceived to be more alien in appearance. Cameron recalled that when one of the main characters, Neytiri, was originally drawn, she had fins, gills, and other protuberances. In addition to feline features, the species was redesigned to look more like humans so audiences could relate to them better.
According to Cameron, the appearance of the Na'vi character Neytiri had some specific inspirations and requirements: she was inspired by Raquel Welch's character in Fantastic Voyage and by Vampirella, noting in the latter's case, "the fact [Vampirella] didn’t exist didn’t bother me because we have these quintessential female images in our mind, and in the case of the male mind, they’re grossly distorted. When you see something that reflects your id, it works for you.... Right from the beginning I said, 'She’s got to have tits,' even though that makes no sense because her race, the Na’vi, aren’t placental mammals. I designed her costumes based on a taparrabo, a loincloth worn by Mayan Indians."
Cameron has described Avatar as more "science fantasy" than true science fiction and has said that he would explain in the novel for the film why in the fictional universe the Na'vi look like humans.