Most Halloween desktop backgrounds are either pumpkins, witches or other type of festive cliches.
Happy Halloween takes another tact on things by merging a pumpkin into a skull to create a rather eerie glare from your desktop. The skull has a bit of blood dripping from it and Happy Halloween emblazoned across the bottom meaning this is not one for the kids. It's only available in 1024x768 resolution, though.
Happy Halloween is a festive desktop for all those tired of the same old clichés and looking for a desktop background a bit more authentic.