Classes That Permanently Transform You

[kevin video]

So I know of the Green Star Adept, the Dread Necromancer, and the Walker in the Waste, but are there any other classes that change you into something that gives you full fortification, or immune to crits, etc like the above three? I know monks turn into outsiders, but I'm talking about undead, constructs, oozes, etc. Stuff that has immunities.

[zook1shoe]

That ex-PrC in Unapproachable East, Thrall of Zuggtmoy, verdant lord, forest master (maybe)

those are the ones that come to mind

[Concerned Ninja Citizen]

Elemental Savant turns you into an Elemental (big surprise, right?) which is immune to crits. At the cost of 2 lost caster levels.

Warforged Juggernaught turns you into a full construct, albeit you have to start as a Warforged so you're half way there already.

[ketaro]

Doesn't the one that slowly turns you into an Ooze count?
Something related to Jubilex or however you spell it in Book of Vile Darkness.

Not sure but similarly, Oozemaster in Masters of the Wild? Though I think thats just turn/rebuke related stuff, not sure.

[Concerned Ninja Citizen]

Thrall of Jubilex, from the Book of Vile Darkness, as mentioned above by Ketaro, sort of counts. It grants you immunity to crits at 10th level and the fluff for the ability is that your form is so fluid you no longer have a discernible anatomy to crit but it doesn't actually turn you into an Ooze.

Warshaper grants a similar immunity to crits at 1st level and doesn't require being a thrall to a demon god, though it does require you get a shapechanging ability from somewhere. 

Oozemaster, however, does change your type to Ooze and grant all the associated immunities, also at 10th level. It's a 3.0 class, though and a 1/2 casting class as well.

[Maat Mons]

Checking this thread, in the spoiler labeled “classes that change type,” should help.  Any of the ones that turn you into a construct, elemental, ooze, plant, or undead should work, with the notable exception of renegade mastermaker, since it makes you a living construct. 

[kevin video]

Thanks for the help, everyone.