The wallpaper is a very well done image of a spooky candlelit room (the artist is Eric Knight Holbrook); the spooky music that shows up occasionally is taken from Danny Elfman's "The Legend of Sleepy Hollow" soundtrack.
The cursors are unobtrusive: you get a shimmering arrowhead for a pointer and a small book for a text cursor. The icons are clever "negatives" of spooky images like a frightened cat, the grim reaper, and so on. Windows and menus keep their white background and title bars get varying shades of brown.
Installation: Unzip the theme archive into Program Files/Plus!/Themes; then right-click your desktop, select Display Properties, and choose The Raven from the drop-down Themes menu.
Note: The theme package includes startup and shutdown screens that don't work with XP.