Shimeji is japanese desktop mascot program that makes a bunch of characters wander your screen and play around. You can get it at [link]
I took the Shimeji source code and made a Shimeji English Enhanced (Shimeji-ee) version. I translated everything to English (including the configuration files), added a right click menu to force the Shimeji do the actions you want, and added support for using multiple types of Shimeji characters at once. It's all working.
You can download it from here: [link]
But make sure to read the readme first: [link]
If someone would like to write some guides, program in more features (or take much needed look at memory usage), or add new image sets, you can join the project and contribute at the Shimeji-ee home page.
Here's the project's homepage: [link]
I also converted a set of Shimeji I had on my hard drive (I don't remember where I originally got them though) to Shimeji-ee image sets. To use them, just copy the character named folders to the Shimeji-ee img directory. It's really easy to convert Shimeji to Shimeji-ee image sets yourself, you just need to rename and copy the old Shimeji img folders to the Shimeji-ee img folder. See the program readme for more information.
Here's the large file of 80 or so Shimeji-ee image sets: [link]
Characters like Adachi and Aizen have special configuration files, so you may want to take a look at their folders.