I'm interested in making a Lycanthrope NPC for my upcoming campaign. I want to do my best to keep with the core rules and such, so I don't confuse myself. When it comes to picking up feats, the 3.5 Monster Manual says to add the base creature's HD to the base animal's HD to find out how many feats it should have.
Base animal is the Dire Wolf Base creature is a Human
He's essentially at level 1 (class level, anyways). I've also decided to go with HD 7, for the dire wolf. But of course I don't know what that really means.
I can't find out what the HD does to affect the character. It seems like the books assume I'm supposed to already know this.
Any help would be greatly appreciated. Thank you very much.