Lagiacrus

A monster that will be featured in Monster Hunter 3, this creature's name is currently unknown. It is skinny and serpentine, swimming gracefully in waters. He seems to have cristals on his back wich can glow in the dark. This monster can likely survive outside the water, so players may be able to face off against him while on land or underwater. More information may be revealed at the Tokyo Game Show, where MH3 has been announced playable. Despite much speculation, very little is known about this mysterious monster.

Link to the MH3 Trailer:

Link to Unnamed Sea Monster pictures :

Link to Unamed Sea Monster video: