This is derived from the 2D artwork by seanmichaelragan in his "Escher-Style Tessellating Lizard" thing.
I liked the look of it so much that I thought it would be fun if I brought it into the 3D world while still keeping it sharp and angular. The original design (shown in blue) will need support to print, but the "Flat Bottom" version (shown in yellow and green) does not and still looks cool. Both versions have been modified with a small negative offset so that they will interlock in their printed form, even if your printer overprints slightly.
UPDATE April 04, 2015
Added EscherLizard3D_FlatBottom_FlatTail.stl. This is a flat bottom version and also keeps the tail at the same level as the body. This prints nicer when printing scaled down versions since the tail will not get all "melty".