Bahamut

A giant Archadian warship.
No. 1 Sky Fortress Class Airship. Belonging to the Western divisions of the Archadian Imperial Army, a mobile fortress and tactical base, under the control of the commandant of the Archadian forces, Lord Vayne. This was the last sky fortress designed by Dr. Cid, powered both by ordinary skystone and manufacted nethicite, the latter absorbing Mist from its surroundings to generate the massive amounts of energy the fortress requires to function.
Note that Bahamut is a regular (though powerful) Esper in RW.