Concept Art: Tortoise Alligator Giant Creature

A concept of a giant tortoise alligator (Tortugator) hybrid creature. It's has reptilian characteristics but at the same time can breath well deep under water due to its unique gills. It is also a fast swimmer due to the creatures flipper like feet and tail fin. In land it can cover a lot of ground due to its size and has a rocky like textured hard shell.