The hammerhead titanothere (Angtsìk in Navi) is a large hexapodal herbivore whose massive, low-slung head features bony projections on either side of the skull, similar to those of hammerhead sharks and their bodies resemble the Brontotheres of Earth. These protrusions are often used to push and destroy objects: a single sideways thrust of the neck being sufficient to down a significantly sized tree. The titanothere has exceedingly thick, gray skin. There is a small "fan" feather structure on the head that it flares up as a warning symbol seen in the film and in the video game. The creature, which resembles a cross between a rhinoceros and a hammerhead shark, is easily aroused. Its hide is impervious to small arms fire, though firing on it is known to anger it. This massive, grazing creature travels in moderately large herds or packs of 10–20 animals. Avatar creature designer Yuri Bartoli explained about the creatures colorful threat display: "Originally, the hammerhead just had to be a huge creature, big enough that even a thanator would think twice about attacking one. A threat display is meant to be seen, so it required bright colors that would stand out against its more muted body". It is moderately social, but also extremely territorial and hierarchical. A soft ungulate mouth is protected by a rigid, beak-like jaw structure. The species is scientifically known as Titanotheris hammercephalis. In the climax of the film, a group of hammerhead titanothere assist the Navi in their battle against Colonel Miles Quaritch's army.