An insidious virus that primarilly infects Windows boxen owned girls who if they were anime characters, would have eyes the size of saucers. Produces a small animated sheep that walks along the taskbar occasionally forming daft animations. If more than one copy of the e-Sheep virus is running on a machine, they will interact with each other. Probably harmless, but just to be on the safe side, if you want a desktop pet, stick to Neko.
I believe someone has made a Half-Life model based on it.