This is Kuzco, my alpaca guinea pig. Squee, yes?
And here we see a kangaroo struggling through all the stages of "is this thing fun or not?" disorder. What a terrible, terribly entertaining sight it is.
Occasionally I give my kitties a fresh catnip treat (admittedly partly for my own entertainment), Here is Sasquatch going through all of the stages of catnip. :-) Larger version here: http://www.flickr.com/photos/najjie/4566548774/sizes/o/