Sgt_Kickaxe - 8:47 am on May 24, 2012 (gmt 0)
This is possibly a by-product of the penguin update. You'll remember that on the day of the update, and for a few days after, natural serps were a mess. The human raters must have been busy and the image directory isn't as important to Google but I'm sure they'll iron the image results out too.
Hopefully they get to it soon, any perceived weakness is sure to get pounced on harder in the future.