These creatures started to emerge from a sheet of paper which had a couple of lines on it, from trying out a pen to see if it would work. I then added some more random lines and squiggles and more creatures emerged. Then I found, on the internet, that someone, a colleague in the field of innovation consultancy, has already patented this idea (ok, not really). Check it out: http://www.jpb.com/doodles/exercises.php
Just doodle it 