This is Creatures of the Night: Ghosts (1997). The cool thing about ghosts is that anything can become one — something that has mostly been overlooked in D&D up to this point. There are 13 ghosts (classy!) described in this book, with full backgrounds and a short adventure that, generally, culminates with them being laid to rest. Helpfully, they are arranged in order of threat, from least to greatest. While all of these are set in Ravenloft, there is very little here conspicuously tying the spirits to that campaign setting, so you effectively have 13 scenarios you can use for any D&D campaign. One a year, every Halloween, for 13 years?

Like the vampire book, there is a good deal of creativity on display (perhaps a bit more, since this book features a larger group of contributors), making for unusual and unexpected hauntings. Some favorites: the ghost of a kid who witnessed a murder and whose fatal headwound allows his spectre to say just three words; the ghost of a werewolf, who can be both phantom man and phantom wolf; there’s also the ghost of stone giant who is possessed by another ghost, which is kind of wild. My favorite is the unfamiliar, though — the opposite of a familiar, who is called forth as an aid, this spectral black cat is an unwanted guest that brings trouble.

Nice art throughout by Mark Nelson and Michael Sutfin.