Fiend Folio
The Fiend Folio was a Monster Manual splatbook for Advanced Dungeons & Dragons 1st edition, which served to gather up the various monsters that had been submitted to D&D in the pages of White Dwarf by that point in time. Most of these monsters have a rather poor reputation and have fallen into obscurity, although a few gems were born amongst the dross, such as the Githyanki and the Githzerai. A 3rd-party company called Necromancer Games released a spiritual successor to the Fiend Folio in "The Tome of Horrors", which adapted many, if not all, of these monsters to Dungeons & Dragons 3rd Edition. Others were brought back for Pathfinder. With the release of Dungeons & Dragons 5th Edition, many of these monsters are starting to be revived and return to the spotlight.