Based on Hurricane Ryu Hariken's illustration of Mogu, the monster bears resemblance to a dragon. Additionally, Mogu has something spiky on its forehead, at least one claw, a pair of wings, and a sharp, forked tail.
Not much is known about Mogu except that it can fly and fire some type of projectile attack from its mouth. It also appears to have a sharp tail, that may be used as a weapon, as well as razor sharp claws, and a crest of spikes.
Mogu was planned to appear in two movies, those being Destroy all monsters and The Return of King Ghidorah.