The Green Book of Murthock
A resource for any game based on the Cthulhu Mythos: details of an arcane tome¸ packed full of dreadful lost knowledge and containing spells that could send even the most rational of investigators spiralling into madness. As well as giving full details of a variety of related books and the spells they hold¸ this resource includes some sample pages to give out to your players.
Designed to be usable with any rules system that makes use of the Cthulhu Mythos setting.