This one has been occasionally worked on whenever I had to somehow pass the time in "work"-environments during the past months. Although... on one occasion I was on a train to Belgium, when I tried to work on the skull, snout and eyes instead of utilising the situation for socialising with my temporary roomies and the opossum.
I guess my only motivation to ink my doodles is the fear of the graphite lines smudging, when I carry my drawings in my notebook for too long.