Animal companion rules.

[Doomboy911]

I am a ranger, a special archetype called the beast master. I am currently level six with one pet occupying one level of the three I currently have available. It is a small falcon ,I have decided that I am in need of a flying mount as it plays into my needs as a sniper. I've chosen a Dire Bat as my second pet. Despite difficulties in finding one I have managed this herculean task. Upon finding the creature the dm told me that I would not be able to get the bat as it had four hit dice, apparently it was off limits. This does not make sense to me. He then went on further explaining that I'd require another level before I'd be able to pick up any other animal companion.

So finding the pathfinder rules rather hazy in regards to hit points and selecting an animal companion I need help.

[Spore]

Well, he's wrong. Animal companions are calculated entirely different than actual animals. You ignore the monster manual entry and build it according to the rules stated in the CRB under druid. Your dire bat would have 2 or two 3 HD (your choice) and anything stated in the table according to your effective druid level for that one companion. Remember that you need to have EDL of 7 to be able to ride the bat as a medium sized ranger.

Since the beastmaster REPLACES the Hunter's bond feature the only valid complaint that the bat isn't listed in the Hunter's Bond feature is null and void because you replace the feature. And the Animal companion feature allows you to choose freely from the druid list.

http://www.d20pfsrd.com/classes/core-classes/druid/animal-companions#TOC-Bat-Dire

Remember to get Boon companion: http://www.d20pfsrd.com/feats/general-feats/boon-companion