National Mystery - Shelled Krakens
From a world once tread upon by the Depauns the Shelled Krakens are among the greatest of all beasts. In length they grow to a maximum of 200 feet long (more youthful full sized ones are instead 180 feet long, they grow continuously until this side very slowly after the 180 mark) and 60 feet in width when taking the great wing like shell bumps on its side into account, its length and width excludes its extendable tentacles. 
 
Its shell is three feet thick, making it neigh impervious to attack outside of its fleshy bits which themselves are protected by a two thick, tough hoods similar in composition to its shell and moved using specialized muscles which connect it to its flesh, using these it can retract its tentacles and its entire head into its shell. Though its description may seem to state otherwise its greatest use is as a ready platform on which to build ships upon as its large jet like propulsion organ allows it to move its cargo and crew along at impressive speeds in a forward direction even in the worst of winds, extending the trade routes greatly as the changing winds need not slow it down all that much when compared to traditional sailing ships. 
 
It has a very efficient metabolism as its shell has the unusual effect of stopping the flow of heat in and out of its body meaning that it can stay warm as long as it is actively using its jet and even when not being fed with trawl nets it can extend two great fans which it uses to entrap plankton and fish. It is also capable of filling its shell partially with water meaning that if need be it can dive down into the water away from threats assuming that its captain has given such an extreme, cargo ruining order. These beasts cost a lot of money to get to maturity as they require a very favorable environment to grow up in so that they reach a usable size and also need to be trained from birth lest they disobey their captains, because of this they are only ever bred to full size using state support. (this means producing them may take a turn, depending on how wealthy the current empire is this may mean only 1 (initial) to as many as 5 (world power) created with one action)