This variation of the Vanishing Leprechaun puzzle was designed by Robin Debreuil of Debreuil Digital Works, an advertising and design company based in rural Manitoba. It has appeared on their web site for some time as the "Magic Puzzle" known as "Who Turned To Doggie Doo"? Robin has been kind enough to allow me to present the puzzle here.
In his correspondence with me, Robin claims to have found the The Vanishing Leprechaun puzzle in a book picked up in Japan. This must have been Puzzlart, by Nob Yoshigahara because it was published in Japan and included the Vanishing Leprechaun puzzle. Robin then designed the one shown here. Robin says the following about an early review.
"I made the puzzle and gave it to my grandfather, who was into those kinds of things, to which he commented, by God, where'd that bugger go? That, having been said, I felt complete."
Along with being artistically unusual, this puzzle clearly shows how the puzzle works. It will still take you awhile to understand what's going on. The picture below shows the three puzzle pieces slightly separated. You can clearly see thirteen people. You can choose to see the puzzle without the separations showing thirteen people, and from there, twelve.