Eerie Art: Cattelan's HIM

In honor of Halloween, I thought I would write about the scariest artwork I've seen -- Maurizio Cattelan's HIM.  I first encountered the sculpture at the Museum of Contemporary Art in Chicago and it was a jarring experience.  The work is meant to be approached from behind so when I first peeked into the gallery I thought it was a perfectly innocuous sculpture of a sweet, innocent boy.  But upon entering further and turning around to look closer at the boy, I was surprised to see the adult face of Hitler.  It's not clear whether he is praying, begging for forgiveness, contrite or steely-eyed.  Cattelan's combination of man/boy qualities in this sculpture too make me wonder whether nature or nurture is more to blame for evil.  It's a powerful experience that raises a lot of questions for me.  What do you think?  What's the scariest artwork you've seen?