Time has passed, so I will allow myself to make a post about Muppets.

I think I last saw this segment when I was six or seven. 

I know it was intended to be funny, but it made me afraid to sleep in beds near walls for years after. I thought a gnu might crash his head through the wall while I slept and sing me a song and/or eat me alive. 

If I understood back then that it was just a head mounted on the muppet man's wall, I'm not sure if I would have been more or less disturbed. A living head with no body is technically much less dangerous than one with, but it should also not exist in this world. And even a regular gnu is unable to sing, but I could (and still do) make an exception to that rule for Muppets.  I suggest you do the same.