I was, as usual, surfing the Internet and all of a sudden I came across this pig, I mean owl. Wow, so upside down animal illusions is a thing? It apparently is, beacause I then encountered this lion or what by René Milot:
And apparently there are other interesting attempts too, you just have to look them up (or down?):
To go even further, Leo Burnett, a prestigious international ad agency, created a brilliant 3-image optical illusion ad campaign for Jeep in France with the motto “See whatever you want to see”. I do.