Awakened animals can take classes. Cohorts do not usually take monster levels but take class levels.
But you are in an area that requires your GM to work with you. If I were you, I'd begin with the premise of the basic animal, then add whatever Awakening does, then hash out with your GM if you can give it more animal levels or must go straight to class levels.
The reason I word it like that, is that you might want the animal level bonus that triggers at lvl 4 or 7 respectively for certain animals. Typically getting larger once HD is over that threshold. - But class levels would not count toward that.
If you had taken a normal Cohort, they would normally be at the maximum level allowed to you. But there is nothing saying they have to. As a newly awakened animal, you could decide with your GM that it is in fact behind on levels and do not yet have any class levels.
You then start tracking XP for it from the number of HD it begins play with and take it from there, adding class or animal HD as agreed with your GM.
See, lots of "GM" in this. :-)
Good luck!
Had way too much fun with a ninja squirel cohort. What class do you plan using?
Had way too much fun with a ninja squirel cohort. What class do you plan using?
Oh. My. God. My GM is going to kill me, but I am totally stealing this for my next character.
I played a squirrel wizard that rode his hawk familiar, but then they came up with this B.S. rule that your familiar could not be larger than you.