Nibirans were tall bipeds. The had white, chalky skin.
The Nibirans' eyes were black, without apparent pupils. An eyelid was on the bottom of each eye. Nibirans also had four nostrils and pointed teeth, but no ears.
Ceremonially, adult Nibirans wore black lines signifying tribal markings. Even infants of the species were marked with these.
As of 2259, the Nibirans were not very technologically advanced. They did possess basic knowledge such as writing, as evidenced by a scroll which they held sacred. According to Admiral Pike, however, they had only discovered the wheel relatively recently.
In 2259, the Nibirans were under threat of extinction from an erupting volcano. Their sacred scroll was stolen from a Nibiran temple by a disguised Captain Kirk, who snatched the scroll to draw the Nibirans away from their settlement below the volcano without breaking the Prime Directive. The plan working, all Nibirans who had been in the temple chased after Kirk. After he and McCoy left the scroll on a tree to end the Nibirans' pursuit, the Nibirans began to worship the scroll as Kirk and McCoy dived into the sea, where the USS Enterprise was hidden.
The Nibirans recoiled in horror as they saw the first stage of the volcano's eruption destroy their home. The retrieval of Spock from the volcano, where he had been deploying a cold fusion device to stop the eruption, necessitated a breach of the Prime Directive; the Nibirans gazed in awe as the Enterprise rose out of the sea and flew to the volcano, and then flew off after beaming up Spock before the cold fusion device detonated. The Nibirans had a clear enough view of the Enterprise to later draw a detailed picture of it in the soil, and began venerating it as a deity. Later, Admiral Pike informed Kirk he had been demoted for "playing God" and interfering in the Nibirans' development. (Star Trek Into Darkness)
Designing the species
Months of careful planning were required – by Lead Creature Designer Neville Page, Makeup Artist Heather Langenkamp and the rest of the makeup team which worked on Star Trek Into Darkness – before the Nibirans' visual aesthetic could be agreed upon. One potentiality was using CGI for the facial designs. "With the expense of computer-generated art for film, and the fact there was going to be 20 of these tribe members," explained Langenkamp, "I think they quickly decided they wanted a great make-up. Neville came up with some good ideas about creating a primitive tribe." (Star Trek Magazine issue 172, p. 93)
According to Neville Page, "The thing that really drove [the Nibirans' appearance] was the find of a particular guy to play our main Nibiran. His physical state is so interesting and unique that it allowed us to do very little makeup work to create a really unique creature."  This influential actor was Jeremy Raymond, whose pronounced cranium, strong jaw and highly developed neck and shoulder muscles were particularly inspirational when it came time to design the extraterrestrials. (Cinefex, No. 134, p. 77) The performer recalled that – even before he knew which part he would be playing in the film – the makeup artists asked him "to send down a bunch of reference photos for them to draw conceptual sketches on top of."  David Anderson said of Raymond, "He became the model for all the Nibiran artwork that Neville produced." (Cinefex, No. 134, p. 77) At a production meeting regarding these concept images, Director J.J. Abrams issued the suggestion, "Just... before you get into adjusting his nose or changing things, let's just look and see what he looks like. It'll be great to sort of find something with the most basic version of him, so he can really perform it." Moments later, it was humorously realized that an initially unrecognizable closeup of the early extraterrestrial design centered on the alien's crotch area.  Shortly thereafter, Raymond began participating in makeup tests for the species. 
With the vegetation on the Nibiran island having a striking red color, a skin color for the aliens themselves also had to be decided on, as did the texture of the skin. Recalled Heather Langenkamp, "What we came up with is this white, chalky skin that was very flakey, like mud was all over it. But coming up with this mud that was going to stick on an actor's body all day long, look the same all day, and not be reapplied, was very challenging. One of our artists, Jamie Kelman, really spent a good four weeks with a gentleman, applying different formulas of this clay every day. We also needed a make-up you could do within five hours [....] It was very challenging." Other necessities of the "mud" were that it had to be made from entirely natural materials and that these could be washed off easily. (Star Trek Magazine issue 172, pp. 93-94)
Working from the concept drawings done by Neville Page as well as from lifecastings of Jeremy Raymond, David Anderson's makeup team ultimately created the Nibiran makeups. Specifically, Jamie Kelman developed full-body latex and clay makeup for Raymond and multiple stunt performers. (Cinefex, No. 134, pp. 74 & 77) "Of course the incredible special effects makeup was the result of a lot of hours of hard work by David Anderson and Jamie Kelman," noted Raymond.  "So our Nibirans – of all the things that we were designing on the show, in terms of character – were probably one of the most collaborative and irritative designs," commented Page. "This particular design was very challenging because it had changed over the course of time, from the very, very beginning of the film, when it was all CG, to now, where it's actual actors in makeup."
Jeremy Raymond was interviewed while the base layer of white "skin" was being brushed onto his body; still to be applied was some mud and costuming, before J.J. Abrams saw the design and gave his comments on it. Upon witnessing the makeup, Abrams stated, "I would argue it's probably a better thing to just go... all mud, all white, and then the mud paint stuff."
Similar to how the creation of the Nibiran makeup had been a lengthy process, its maintenance was also to take up much time. One Nibiran-playing performer observed, "They're very well-maintained aliens."  Heather Langenkamp estimated, "It ended up being just about five hours to apply on each guy." (Star Trek Magazine issue 172, p. 94) Anderson commented, "It took a team of 30 A-list makeup artists six hours to ready the tribe. We flanked Jeremy with prosthetic lookalikes. Behind them, we used vacuformed masks of the same sculpture that actors wore beneath hooded robes. Anytime a Nibiran had to speak, we changed Jeremy's tribal markings and flipped his position in the group so he played all the speaking roles, and the characters appeared identical beneath their paint. (Cinefex, No. 134, p. 77) A total of about twenty to thirty Nibiran actors were on set. 
Aspects of Nibiran culture
The design of the Nibirans relied on contributions from many different departments assigned to Star Trek Into Darkness. Having been granted first-hand experience of seeing the creation of the Nibiran species, Jeremy Raymond admitted, "What was amazing to me was to see how organically the whole process was evolving – the performance would inspire changes in makeup, which would inspire changes in the costume, which would then shape the performance in new ways." Aside from himself, Page and J.J. Abrams, Raymond pointed out that a few other people "were absolutely instrumental to the creation of the Nibirans," not only citing David Anderson and Jamie Kelman but also saying, "[Costume Designer] Michael Kaplan and his wardrobe team created a stunning array of costumes and designs that were wonderful to play around in." 
Michael Kaplan used draped and dyed fabric for the Nibirans. "We wanted something that was not too sophisticated, so that it would be very recognisable as a primitive race," he stated. "The planet is all red, so I chose saffron gold, because it pops out." 
Nibiran weaponry constituted the first material from Star Trek Into Darkness that prop designer John Eaves was assigned to work on, though he wasn't given much details about the species to take inspiration from. "The first volley of designs centered around a primitive alien civilization who used blow guns, clubs and spears [....] So, with that said, I was off to research dart guns and a host of other primitive weapons and give them a bit of a Star Trek twist," Eaves related. He also noted that, as the film developed and underwent subsequent revisions, "the grand alien nation [...] shrunk in size drastically to fit budget constraints," resulting in many prop concepts which he had developed ending up by the wayside. Unused concepts for Nibiran tools that were thought up and illustrated by Eaves include saddles, a "rock-throwing running stick," as well as other examples of "savage gear" including a short spear and a longer equivalent, stones made easy for throwing with fabric tied around them, a "shell club" and a sling. The artwork additionally encompassed at least four pages showing illustrations of blow guns. 
Industrial Light & Magic enhanced live-action close-ups of Nibirans by adding bird-like nictitating membranes which flickered upward across the aliens' eyeballs. Additionally, a group of CGI animators at ILM replicated Nibirans using digital animation and motion capture technology, as J.J. Abrams wanted a massive throng of Nibirans to be shown chasing Kirk and McCoy. (Cinefex, No. 134, p. 77) Abrams wanted the digital doubles to be present in the background.  "I volunteered to shoot motion capture on our stage at ILM," admitted ILM Animation Supervisor Paul Kavanagh. (Cinefex, No. 134, p. 77) He consequently donned a motion-capture suit.  "I got into character," said Kavanagh, "and acted out multiple action clips in our 30-foot motion capture volume. It was quite exhausting." (Cinefex, No. 134, p. 77) He therefore thought he was perhaps not the best choice for performing the motion capture, though he nonetheless had fun doing so, later recalling, "I ran around the stage doing the praying and getting on my knees, which was quite funny.”  Animators used keyframe animation to augment the motion capture data, prior to digitally inserting a crowd of 120 rampaging Nibirans. (Cinefex, No. 134, p. 77)
For the scene showing the Nibirans awed by the Enterprise, ILM artificially dwarfed the aliens in relation to the vessel. Although such an effect was generally avoided because it can lessen the seeming reality of a shot, the creative staff thought it appropriate for the view of the Nibirans facing the Enterprise's comparatively enormous deflector dish. "We wanted to make the Nibs feel very small in the face of this gigantic object," mused ILM Visual Effects Co-Supervisor Pat Tubach, "and that causes them to abandon their religion to worship the Enterprise." (Cinefex, No. 134, p. 81)