Lashtongues have blue-green fur-like plumage and, unlike other dinosaurs, have wings instead of forelegs. Although their snout resembles a beak, their jaws are filled with rows of small teeth, which sets the Lashtongue aside from birds. Another feature that characterizes the tartarian Lashtongue is the troath pouch located at the underside of their snout. This pouch is used to net fish in Tartarion's rivers, allowing this species to subsist on a fish-diet despite being unable to swim.
Occasionally, a Lashtongue will be unfortunate enough to net a tartarian Viceclamp-Lamprey, which most of the time results in the Lashtongue's death. The lamprey will eat it's host's tongue, replace it and make the host's pouch it's new home. In the rare cases where the Lashtongue survives this gruelling procedure, the, involuntary, symbiosis opens up a myriad of new possibilities for them. No longer is the Lashtongue forced to patiently stand in rivers, it's mouth open, waiting for fish to swim into it's gullet. The lamprey-tongue is able to reel in prey with it's hook-like mouth, allowing the Lashtongue to catch prey from a greater distance and easier. More prey allows both animals to grow to humongous proportions, allowing the Lashtongue to compete with the predators that originally forced it's ancestors to adapt it's diet.
The greatest and oldest of these unlikely couples are said to be able to evenly match lesser dragons, acting as if they were one single creature instead of two. In fact, the Irasha knights, who often use the Lashtongues as steeds, swear that, after a few decades, the flesh of both creatures becomes so intertwined that they become one.