From the front of the book:
The Forgotten Realms has been a living breathing world for decades, brought to life by the fertile mind of Ed Greenwood in 1967 and nurtured and grown by countless authors and game designers since its publication in 1987. Between 1987 and 2000, TSR, Inc. and Wizards of the Coast released an enormous volume of game material for the Forgotten Realms under the aegis of the 1st and 2nd Editions of Advanced Dungeons & Dragons. In 2000, Wizards of the Coast updated the venerable Dungeons & Dragons game, with the release of 3rd Edition or "3E." In 2001, Wizards of the Coast updated the Forgotten Realms campaign setting to 3rd Edition as well.
In the opinion of the authors, the introduction of 3rd Edition is a welcome addition to the ever-growing Forgotten Realms, for the system's flexibility allows game designers to better represent the endless variety of life that dwells in the Forgotten Realms. However, the downside of the new version of the game is that, given the volume of game material produced under the banner of earlier editions, Wizards of the Coast will never be able to update all of it to the new system. This discordance is very unfortunate for the Dungeon Master running a campaign set in the Forgotten Realms, for it is the vast quantity of Realmslore that makes Abeir-Toril feel like a living, breathing world.
As a first step towards addressing this gap, the authors are releasing a bestiary of over 100 monsters native to the Forgotten Realms from their own personal files. Some of the creatures detailed are new, while most are updated from earlier editions of the Forgotten Realms. Many of these monsters were updated or created for the authors' own campaigns, as part of half-finished article submissions, or landed on the cutting room floor during the editing of a game product. As this project came together by happenstance and not design, the selection of monsters is admittedly haphazard. Many of the monsters included herein are minor species unlikely to ever get written up in an official Forgotten Realms product, but crucial nonetheless to making a Forgotten Realms campaign feel “complete.” Future volumes of this bestiary (should they come to fruition) will hopefully contain a more varied range of monsters.
Errors, including errors of attribution and calculation, will be corrected as needed in future versions of this file. Until then, Sword High!