Do Animal Companions increase in size...

[Inconsequenti-AL]

... as they gain bonus HD from the druid advancing?

Sorry if this has been done to death before, but I couldn't find it.

I was statting up a 3rd level Druid with a Wolf animal companion - the 2 bonus HD would advance it to large (4-6) HD as per the wolf Advancement in the monster manual. I applied the mods to make a large 4 HD wolf and it seems a bit too vicious... frankly, from a melee standpoint, I think it's stronger than a 3rd level melee character. It all seems a little wrong?

I'm not sure what the intention was. Anyone able to help?

Bonus HD: Extra eight-sided (d8) Hit Dice, each of which gains a Constitution 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.

 

[Caliban]

No, they don't increase in size. You aren't actually advancing them in HD, although they get similar benefits.

Think of it as a prestige class for the animal.

 

[sledged]

No, they don't increase in size.

It's clearified in the FAQ on page 4.

 

[Inconsequenti-AL]

It did seem a touch on the strong side.

Thanks for clearing that one up!