What an interesting theme! When I googled Pierrot for images there were so many--and all so different! Sad, happy, cute children in clown costumes, internationally famous actors, elegant dancers, tragic faces, and not just a few creepy ones.
I chose these , from Wikimedia Commons, both used with permission of the photographers and altered with Fotosketcher, my new favorite free toy.
The grungy diamond pattern is from Bittbox and the rest was done with brushes, filters and blending.