Today while browsing another desktop thread on /g/, I saw a user who had a cat roam around his cursor. After googling a bit I found out that this was the name of a package called Neko.
The wikipedia link describes it best.
…[Once run] the pointer could be modified to various cat toys such as a mouse, fish, or bird. When Neko caught up with the pointer, it would stare at the screen for a few seconds, scratch an itch on its body, yawn, and fall asleep until the pointer was disturbed. In windowed mode, Neko would stop at window boundaries and scratch at the edge of the window.
I downloaded the package and now Neko is happily sleeping at the corner of my screen. Note that oneko isnt in the official repositories, and I downloaded it from the Arch User Repository.
$ yaourt -S oneko
Very very cute!