Krita and the accidental painting.
It has been a long time since I checked out Krita. I Painted this in Krita 3.1.1 on Mac Yosemite, versions for Windows as well and of course Linux; all are free. The bird took about six hours, give or take, and the program was not shut down for two days. I had one lock up during export of the final PNG save, no problems with the tools or app other than that. Be sure to save often, just in case. I used the following brushes, available here:
Concept Art & Illustration Pack
Cazu Brush Collection
Just playing around I created this in no time:
Further playing ended with this:
Of course this gave me an excuse to continue painting:
and finally, the end result: