The Arrowtongue is one of Darwin IV's most ubiquitous alpha predators, growing to roughly 26 feet in length and 8.2 feet at the shoulder. A mostly solitary hunter, the arrival of its dark form upon the plains presages a short and furious pursuit almost always ending in the death of some hapless Thornback, Prismalope or Littoralope. Bearing an enormous darting tongue, this aggressive liquivore was frequently spotted by expedition-members concealing itself amongst the electrophyte beds, taking advantage of those colonial animals' electrical discharges to discourage the herds from approaching too closely. It is believed that the creature emits its ranging pings in concert with the electrophytes' discharges, a habit that probably obscures its point of origin from prey animals. Bioluminescent patches are aligned on their backs, thanks to a symbiotic relationship with an unspecified microorganism. They stand on a pair of muscular legs, and they do posess small tentacle- like arms.
I really wanted this creature to be big and threatening, my version of what might have evolved along T-rex lines on another planet. The notion that what we were witnessing on Darwin IV was the evolutionary equivalent to the late Cretaceous era on our own planet was never far from my mind. -- Wayne Barlowe, creator of Expedition