D&D 3.5 Knowledge(Monsters), skill - New

Players Handbook

Knowledge Monsters(Int; Trained Only)

This is a new area of knowledge. You know a vast amount of information about all kinds of exotic and strange creatures of the land. You learn specific information about defeating or combating creatures in combat, but does nothing for knowing a creatures culture or information that would be useful outside of combat.

Note: The DC is calculated as 10 + Hit Dice +2 per each book away from the Monster Manuel. So for example if the monster was from the MM2 and had 5 hit dice the DC to know info would be DC17.

Class Skill: This is a class skill for the Fighter class and Warforged race regardless of what class a warforged takes.