In February 2011, I taught myself Processing by building this guy. I'm sure there are many optimizations available, starting with existing particle libraries, but figuring out the fur from scratch was most of the fun.
Sometime between then and 2013, he's developed a quirk where he gets a tuft of fur on his chin in Chrome (but not Safari). Maybe someday I'll track down what he's allergic to.
I don't expect it to be of value to others, but source can be found at OpenProcessing.