Animal companion, driving me bonkers

[Voyd211]

So, I'm currently making a tiefling druid, as stated in my earlier "Poison" thread. However, a new problem has come up: Namely, I don't know how much health the AC is supposed to have.

Help?

[Bbauzh ap Aghauzh]

It is in the FAQ

HERE

[BigNorseWolf]

(4.5 X Critter hit dice*) + (Con X Critter hit dice) + (other such as toughness)

*Round down.