1.3 - 2 meters tall (at shoulder)
Tauntauns are a species of snow lizard found roaming the windswept snow plains of Hoth. The Rebel Alliance domesticated the swift creature during their stay on the ice planet, and used the animals for patrol duties outside Echo Base. The animals came in useful as the Rebel technicians had difficulty adapting their repulsorlift speeders to the subzero temperatures.
Both Luke Skywalker and Han Solo rode tauntauns on Rebel patrol missions, planting a network of life-form sensors along Echo Base's perimeter. Though tauntauns are sure-footed and well equipped to handle Hoth's daytime temperature, the chilling extremes of a Hoth night will prove deadly.
Perhaps the most visible of Hoth's indigenous lifeforms is the spitting, gurgling tauntaun. They are well adapted to the blizzard environs, with remarkably cold-resistant blood and inner organs and a thick layer of insulating fat and fur. Tauntauns have four nostrils; the larger pair brings oxygen into the bloodstream during physical exertion. At night, when the tauntaun sets down to sleep, it seals off the larger set to keep snow out and retain heat, and uses the smaller pair to breathe.
Tauntauns are omnivorous, feeding on a type of fungus that grows just beneath the frost layer. They are known to eat meat when necessary, consuming smaller animals like ice scrabblers or Hoth hogs. They exude some of their waste products and oils through specialized ducts on their skin, giving them a very foul odor.
Female tauntauns grow horns and compete for mates by butting heads. Tauntauns tend to be ill tempered, so those attempting to domesticate them often neuter the females. Aside from charging with their horns, a favored method of tauntaun attack is spitting. Though their saliva is not corrosive, the presence of a liquid near the eyes in subzero environment can definitely be inconvenient.
Tauntauns are scattered throughout the Hoth globe, resulting in evolutionary variations. Some tauntauns are distinctly more reptilian in appearance, and size and fur-length also varies.
The tauntauns seen in The Empire Strikes Back are a combination of stop-motion miniature and full-sized puppet, depending on the requirements of the shot. For long shots of the tauntaun running across the frozen plains, a stop-motion miniature was painstakingly animated one frame at a time and then composited into painted, miniature, or live action backgrounds.
For the close ups, where the tauntaun's rider would be visible, the full-sized puppet was used. The puppet was quite articulated, and featured a track that would allow it to "run" for short distances. When the production went to Finse, Norway to shoot, however, the puppet froze up and most of its features didn't work.
In Return of the Jedi, Jabba the Hutt has a stuffed and mounted tauntaun head as one of his grisly trophies, right next to the frozen form of Han Solo.