I really liked the Velociraptor Business card by Cleven but i have no need for a business card, so i "un-business-carded" it, extruded it and made it much bigger so it assembles effortlessly and looks cool on your desk.
It is ca. 23cm in length and 11.5cm in height.
The head parts (The parts with the teeth) produced a couple of misprints on an Ultimaker 2, maybe it is a good idea to print them separately.
If you want to scale it just scale the STL file, it should still be intermateable afterwards.
I included the vector forms (Inkscape SVG file) which i extracted and corrected from the .dxf the original author included.
To extrude the SVG in OpenSCAD (Which can only import STL or DXF files) i used this excellent Inkscape extension: Inkscape OpenSCAD DXF Export
Also check out this longer tail for balance from galiettd!