Digital Denizens: Challenge Rating One

From the introduction:

Digital Denizens: Challenge Rating One introduces new creatures of Challenge Rating 1 and lower for use in d20 System fantasy games. Some are new twists on old favorites, while others are original creations designed to surprise DMs and players alike. Most of the creatures and nearly all of the skills, feats, and special abilities can be easily used in any fantasy setting, but plenty of background is provided to help DMs integrate the material into their own campaign worlds. Some DMs may wish to introduce new creatures sparingly, using them to catch jaded players off-guard, while others may wish to make them an essential part of their games’ flavor.