Dragon on Egg: -

Found a free Version of this mesh and  Fixed for 3d printing.  Also added UV textures to mesh.  

Sometimes the only way to fix models is to subdivided the mesh till its well over 3million tris and then go thorough the process of clean up, triangulate, fill and manifold.  Ended up using three different programs just to get the mesh to fix without ugly artifacts.  Its way easier and quicker if you can fix the model at a low poly at the start.  But not the case for this beast.  When you find models for free online that come from a paid source (such as this one)  you just have to work with what you got.  This was a mess.