optical illusion sites ?

[tigga]

Hi all, im looking for a sight that has an optical illusion i once recieved as an email. It tells you to stare at an image but then it turns into some monster and frightens the life out of you (obviously its not really an illusion - just a daft joke) oh well im bored and want to get a few people with it.
Hope that makes sense.

[Daave]

www.tekzoned.com

also has the original crazy frog thing!

[kempie]

http://www.michaelbach.de/ot/

[tigga]

thanks guys !