Dragons

[Alaltus]

http://na.finalfantasyxiv.com/world/cities/mor-dhona

As the imperial fleet advanced into the skies above Silvertear Lake, the largest inland body of water in Aldenard, it was met with a wholly unexpected sight. Midgardsormr, the dragon deity of the lake, had arisen, summoned by a hand unknown. And as if to answer the mighty wyrm's call, a host of dragons flew in from the northwestern reaches of Dravania and fell upon the Empire's forces. The air was filled with the deafening roars of cannons and dragonkin alike. Locked in a deadly embrace, the thunderous impact of Midgardsormr and the dreadnought Agrius tolled their mutual demise. Thus ended the Battle of Silvertear Skies.

Even now, the carcass of the immense wyrm lies entwined with the wreckage of the Agrius in the center of the lake, a towering monument to the ferocity of the conflict. Ever since that day, the lands of Eorzea have continued an inexorable fall into chaos...

Seems that this update confirms Migardsormr and the Agrius' presence in Mor Dhona ^^?

[Catapult]

http://na.finalfantasyxiv.com/world/cities/mor-dhona

As the imperial fleet advanced into the skies above Silvertear Lake, the largest inland body of water in Aldenard, it was met with a wholly unexpected sight. Midgardsormr, the dragon deity of the lake, had arisen, summoned by a hand unknown. And as if to answer the mighty wyrm's call, a host of dragons flew in from the northwestern reaches of Dravania and fell upon the Empire's forces. The air was filled with the deafening roars of cannons and dragonkin alike. Locked in a deadly embrace, the thunderous impact of Midgardsormr and the dreadnought Agrius tolled their mutual demise. Thus ended the Battle of Silvertear Skies.

Even now, the carcass of the immense wyrm lies entwined with the wreckage of the Agrius in the center of the lake, a towering monument to the ferocity of the conflict. Ever since that day, the lands of Eorzea have continued an inexorable fall into chaos...

Seems that this update confirms Migardsormr and the Agrius' presence in Mor Dhona ^^?

That actually sounds like a v1.x description and is largely well documented... mostly by Erik.
But there is something new in there. It describes Midgardsomr as a "deity", meaning it does fall into a gods-related category even if it is different to the primals in origin and nature, and that is was in fact summoned rather than just choosing to rock up for the party.