Moving underneath the surface in the fourth quadrant of the Si Wong Desert, the sand shark encountered a crashed airship which had been headed toward Ba Sing Se, though it never showed itself. Later, after Asami had spearheaded the repair of the vehicle, the creature burst out of the sand, lifting it easily into the air and snapping it in half, before dragging it largely with it below the surface. The beast returned later when the airship crew, Asami, and Korra had manufactured a makeshift sand-sailer and pursued them, its dorsal fin breaking the surface. After two failed attempts to swallow the vehicle and its passengers, the sand shark vanished underneath the sand, only to reemerge moments later, right underneath the vehicle, tossing it up in the air. Although it nearly swallowed the craft, it was deprived of its meal by Korra's last minute firebending attack, which left it eating smoke and caused the beast to retreat underneath the surface.
The sand shark is an enormous creature, surpassing an Earth Kingdom airship in size. It is primarily brown, with a beige belly and beige webbing on its dorsal fin. It has six fins on its belly, two large brown ones in front and four smaller beige ones near its back. The dorsal fin runs nearly the entire length of the animal with a peak in the middle. The animal has expandable jaws with multiple rows of teeth, three rows in both it upper and lower jaw, and a group of teeth in each cheek, all pointing inward.
The sand shark moves underground through the loose sand of the desert; the only sign of its approach is either the sight of a moving dune or its dorsal fin sticking out. It stalks its prey to attack from below, ambushing it in order to swallow it whole. The sand shark is capable of reaching speeds that surpass that of an airbending-powered sand-sailer and is strong enough to leap high into the air.
The sand shark bears a resemblance to a great white shark in appearance, teeth, and hunting style. The main differences are its size and color, as well as its expandable jaws. The shape and expandable trait of the mouth is similar to that of the sarcastic fringehead fish.