Bonus HD of Animal Companions

Question

I have two questions about the bonus HD:

Bonus HD: Extra eight-sided (d8) Hit Dice, each of which gains a Consitution modifier, as normal. Remember that extra Hit Dice improve the animal companion’s base attack and base save bonuses. An animal companion’s base attack bonus is the same as that of a druid of a level equal to the animal’s HD. An animal companion has good Fortitude and Reflex saves (treat it as a character whose level equals the animal’s HD). An animal companion gains additional skill points and feats for bonus HD as normal for advancing a monster’s Hit Dice.

1. The Wolf has 2 HD, while my lvl 1 Druid only has 1; the text only says about Extra Hit Dices (I'm pretty sure he means only the extra dices from the animal companion bonus but I'm asking it just to be sure), does that means that I should consider adding the bonus of lvl 2 Druid (+1 BAB, +3 fort) or none at all?

   In short, does the animal companion gains any bonus at lvl 1 from having more HD than me?

2. Considering the text says "An animal companion has good Fortitude and Reflex saves (treat it as a character whose level equals the animal’s HD"; When he says "treat it" he means "to substitue it" or "add it"? The Wolf has better saves than my Druid, if I were to substitute the saves it would nerf him.

Answer 1

Your druid level is entirely unrelated to your wolf's HD. The wolf gains animal hit dice.

Take a gander at the rules for improving monsters. They explain what happens when you add extra hit dice to a creature - you increase its BAB, HP, and saves, and it gains feats and skills as normal.

However, this does not affect a level 1 druid at all. A level 1 druid's animal companion gains +0 bonus HD. Take the wolf straight from the book, and use it.

Once you reach level 3, your wolf gains 2 extra hit dice. This is basically like him taking 2 levels in the "animal" character class. These hit dice grant him the following improvements:

• 2d8 hit points (plus 4, for the wolf's +2 Constitution modifier)
• 2 points of Base Attack Bonus (for a total BAB of +3)
• +1 to each of its saving throws
• 1 new feat (for passing level 3)
• +1 to any ability scores (for reaching level 4)