According to Savage Species, an anthropomorphic creature doesn't gain feats for its racial hd, only it's class levels grant feats. Is this a retroactive granting of feats or do I treat my first class hd as my very first hd ignoring racial hd and count levels that way for gaining feats?
If you're going by RAW, it looks like you only gain feats for every 3 hit dice total, though not any starting feats.
Eg, a badger barbarian would get no feats, since it only has 2 HD (1 from badger, 1 from barbarian).
When it reaches barbarian 2, it would get its first feat. At barbarian 5 it gets its second feat.
A giant crocodile ranger is in worse shape, since it starts off with NO feats even though it has 4 HD (3 from croc, 1 from ranger). It has to wait until ranger 3 to get its first feat.