Heads that present one character one way up and another when rotated have been favorite illusions for over a century. Here are two heads from a cartoon story I devised about a boy who gets stuck in a weird hotel. The receptionist and chef, (Mr. and Mrs. Turner …. ) seem OK at first, but then transform into two sinister old men when their heads rotate.
For an animation of Mr. and Mrs. Turner see below:
There are loads of great rotating heads at:
http://members.lycos.nl/amazingart/E/6.html Rotating Heads