Based on the original sketch from Lovecraft himself: http://upload.wikimedia.org/wikipedia/commons/8/8d/Cthulhu_sketch_by_Lovecraft.jpg
Dunno. I just felt like painting this. As a practice.
And also because you never need a reason to draw Cthulhu.
Never.
Link
Velantian
"Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn"