Ghosts are also a major part in the game. First of all they are the things haunting Waverly Hills, and also the reason there are flesh craving monsters around. Ghosts are the things that possess the undead people. The main ghosts in the game and those of the 60,000 people that died in Waverly Hills and the ones that haunted and eventually killed. They are the first of the ghosts to get into the undead bodies. But when the virus gets out, all ghosts and sprites have another life to get to, but its not much of one when you get into a continuous cycle of eating people and turning them into the thing they are. If they even had a mind once possessing the bodies, they would regret their decision of joining that body.
Ghosts can be hard to see, they are 'see through' or transparent. You can see the outline of them and the body shapes but it is quite hard, from a distance they can look like a sheet or a curtain (that's how the whole sheet thing came into play) but as they get closer to you, you can make out a person or a figure.