Sandswimmer

Sandswimmers were one of Tatooine's most feared predators, and was a spider-like creature which spent most of its time underneath the sand. To move around, it would use its brightly colored fins to propel it under the sand, though it would most usually be found resting with simply the ridge of its back and a row of eyes showing above the surface. The Sandswimmer's pale exoskeleton helped to serve as camoflage as well as protection from moisture loss in the dry, heated environment. Its broad, brightly colored leg fins also served another purpose besides allowing it to "swim" through sand; when it was above ground, the fins would generally be folded to reduce surface area but, when the Sandswimmer was attempting to attract a mate, it would flare them out. When attacking its prey, the Sandswimmer would grasp onto the target with its forelegs and then attach its sucker-like mouth and drain all fluid from the victim. This process happened so quickly that there was absolutely no need for any paralyzing poisons or other means of immobilizing the victim. Once it has drained its victim, the Sandswimmer would return to the sand to digest its meal.

Behind the scenes
The Sandswimmer was created by Tara E. Murphy, a Star Wars fan, as part of the Design An Alien contest held in the Star Wars Galaxy Magazines. Though the entry was not picked as a winner, it was given an honorable mention in Star Wars Galaxy 7 and so it is not known exactly how canon the creature is.