Lost on Animal Companion levelling

[dyslexicfaser]

So, I need some help to figure out how to change a level 1 dire badger into a level 4 animal companion.

A level 1 dire badger is:

Size/Type: Medium Animal
Hit Dice: 3d8+15 (28 hp)
Initiative: +3
Speed: 30 ft. (6 squares), burrow 10 ft.
Armor Class: 16 (+3 Dex, +3 natural), touch 13, flat-footed 13
Base Attack/Grapple: +2/+4
Attack: Claw +4 melee (1d4+2)
Full Attack: 2 claws +4 melee (1d4+2) and bite -1 melee (1d6+1)
Space/Reach: 5 ft./5 ft.
Special Attacks: Rage
Special Qualities: Low-light vision, scent
Saves: Fort +7, Ref +6, Will +4
Abilities: Str 14, Dex 17, Con 19, Int 2, Wis 12, Cha 10
Skills: Listen +6, Spot +6
Feats: Alertness, Toughness, TrackB
Environment: Temperate forests
Organization: Solitary or cete (2-5)
Challenge Rating: 2
Alignment: Always neutral
Advancement: 4-9 HD (Large)


At level 4, that would mean he gains an additional 5d8 hp plus Con mod (3 for level increase, 2 for being an animal companion), 10 skill points (2x5), his BAB becomes 3 (3/4 as per cleric).

What I don't get is, the size advancement. Does that mean that once he gains 4 HD from level 1 (level 5) he goes from Medium to Large? Or does that mean that when his natural 3d8 HD reach 4d8, he increases in size?

Also, he gets a feat at level 3. Can he take anything? Is there a feat besides weapon finesse (which wouldn't really apply to him) that would let him use his (significantly higher) dex instead of strength on attacks? Or should I just give him Power Attack and be done with it?

Any thoughts or suggestions would be appreciated.

[KIDS]

I believe that you got confused with the Advancement line in MM. Though I don't have time to post whole info now, advancing as animal companion (bonus HD and goodies) does not increase size, so he will not become Large.

Also, what do you mean by level? Owner's effective druid level, badge's hit dice...?

For feats, he can take anything he meets prerequisites for, yes. Gotta run now, I'll check the thread later.

[Zincorium]

If you are not the DM, do not look at the advancement line in the MM. It will never apply to anything you do.

When an ability like the druid's animal companion or the paladin's mount adds hit dice to an animal, that's all it does.

Animal hit dice are describedhereabouts, but essentially they have D8's for HD, 3/4 BAB like a cleric or rogue, 2+int skill points, strong reflex and fortitude saves, and not much else. Just level them exactly like a normal PC otherwise, including feats and such.

[dyslexicfaser]

Well, his druid's effective level is only 1, since a dire badger is counted as -3 levels. But the druid took the Improved Animal Companion feat, bringing it up to level 4. Right? Or am I getting different SRD rules mixed up?

[Lord Lorac Silvanos]

You are right about the effective druid level.

You level them as Zincorium said, but remember that Dire animals have all saves as good.

You simply follow the table outlined in the Druid description and only give it what it says in the description and on the table.

You do not gain ability increases for every 4 HD (you get ability increases according to the table) nor do you get size advancement.

At 4th effective druid level that means an additional 2 HD for a total of 5 HD for fluffy.

Weapon Finesse is certainly a possible choice for a feat.