Ceadeus is the ultimate battle and the reason Moga Village has been suffering from Earthquakes. Ceadeus can be kind of hard to figure out at first because he does a bunch of damage, but he does take a while to kill. If you use a lightning weapons and make good use of the Dragonator and the underwater ballista, he will drop.
If this video was helpful, please subscribe and check out my channel for more MH3U videos and Wii U games. Thanks!