I designed it in inkscape (invader.svg) using 2.5x2.5mm squares as "pixels". Later I outlined it and saved it in dxf format (invaderout.dxf). I then passed it through a simple scad linear_extrude to make it 2.5mm tall. Slice and print.

The diagonals had to have extra "offset pixels" to make them hold together. The eyes are also 1.5 pixels wide to make them a bit larger to (e.g.) thread thick cotton through and put on a keyring.