A creature lurking in the abyss of Naboo, the opee sea killer is an amalgam of evolutionary traits found in other animals. It has armor and limbs like a crustacean, but has the massive hinged jaws of other fishes. The opee is a silent hunter, typically lying in wait, clinging motionless to rocky crags. When it spots a tasty morsel, the creature captures its quarry with a long sticky tongue that drags struggling prey into a mouth filled with double rows of teeth.
The opee sea killer swims via a remarkable example of organic jet propulsion. The opee draws in water through its mouth, and forces it through openings beneath its armored plates, giving it impressive speed over short distances. The three pairs of armored legs assist in this pumping motion, as do a pair of pectoral guidance fins.
The long antenna-like stalks growing from the opee sea killer's head are actually lures that the beast uses to attract prey.
Opees are mouth breeders -- the male opee carries and protects fertilized eggs in his mouth. He fasts for three months as the eggs mature, which then hatch producing hungry young killers. There are reports of the opee's deep sea rival, the colo claw fish, inadvertently swallowing young hatchlings whole, only to be killed when the hungry youngsters chew their way out of their captor's stomach.
Early designs of the opee sea killer showed a creature that was little more than a tooth-filled jaw grafted onto a combination fish and crab body. Later sketches refined the look, though a possible design direction incorporating mammalian characteristics -- a long body and a fin-like tale -- were explored and abandoned. The opee stayed the fish/crab hybrid and the mammal traits were worked into the sando aqua monster designs.