Creatures of Rokugan (2001)

A monster sourcebook for Oriental Adventures. It is worth noting that while it looks like any of the other dual system supplements for both Oriental Adventures and Legend of the Five Rings, it only provides mechanics for the former, not the latter.

Publisher's Blurb:

Shape-shifting tricksters. Foul name-bound demons from the depths of Jigoku. Blood-drinking ghosts. Faceless spirit armies driven only by vengeance. These are only a few of the creatures that stalk the Jade Empire.
Creatures of Rokugan is a great resource for Legend of the Five Rings fans or Dungeons and Dragons® players looking for something new and unexpected. Fans of Asian fantasy will love this book, which contains dozens of creatures familiar to players of the Legend of the Five Rings collectible card game and role-playing game, updated to the Oriental Adventures rules. Also contains advanced rules for playing Naga, Nezumi (Ratlings), kenku, goblins, and other strange races as player characters, as well as new feats and prestige classes for monstrous characters.

Back Cover:
This book is designed to work either as a supplement for Rokugan, the d20 Companion for Legend of the Five Rings, or as a sourcebook of exciting new monsters for any d20 campaign. Are you ready to face the creatures of Rokugan?

They're ready for you.

To use this companion, a Dungeon Master also needs the Player's Handbook, the Dungeon Master's Guide, and Oriental Adventures. A player needs only the Player's Handbook and Oriental Adventures.