Making a Companion Familiar survivable with no druid levels.

[Thanatosia]

OK, So I'm playing a Sorceror/Favored Soul Mystic Theurge, using early entry to go into the class at lv4 (DM allowed Versatile Caster + Highten Spell). Now I'm lv13 and have ran out of Mystic Theurge levels, but I've been planning for this by playing a Bamboo Spirit Folk and buying cross-class ranks in Knowledge(Nature), which conveniently enough let me just hit 8 as I run out of MT levels. SO I plan on going into Arcane Heirophant to continue my double progression, and what I'm loooking at trying to fix is a way to make my COmpanion Familiar have some semblance of survivability. It doesn't need a LOT of hps since I have no intention to make it a front line fighter, I mainly want to use it to deliver my touch spells across the battlefield - but having essentially the HD/Hp of a 1st level DRuid's companion at lv14 just ain't gonna work. Is there any way to get my Animal Companion some survivability? I could hold off on getting one till lv15 if there are any feats that would help out.

[Crake]

I'm afraid I don't believe there's much you can do this late into your build other than seeing if the DM will let you take wild cohort (http://archive.wizards.com/default.asp?x=dnd/re/20031118a) and using that in place of the animal companion benefits, otherwise your best bet is natural bond to up the effective druid level by 3, but really, what you're asking is to gain a whole, scaled class feature without any actual investment, which is just no possible.

That said, how are you getting trackless step to actually get into arcane heirophant? I note you said something about bamboo spirit folk, is that a race that gives trackless step? Because if so, it still wouldn't qualify, because the requirement says "trackless step class feature" so a racial ability wouldn't count.

[sleepyphoenixx]

See if your DM lets you trade in the Companion Familiar for the Urban Companion ACF from Cityscape.
It's basically a familiar with 3/4th of your hp instead of half, and it doesn't cost XP or is gone for a year if it dies. What actually matters most to you is that your effective druid level is only important for the special abilities it gains, so it should work better for your particular build.

Alternatively you can take Obtain Familiar and the Theurgic Bond feat (Dr325) to add your levels in arcane casting classes to animal companion progression, but it's Dragon Magazine content so your DM might not allow it out of principle.

[Chronos]

You could also just ask your DM if you can just ignore that class feature, since it'll make your familiar considerably worse, and a normal familiar would be much more survivable.