3.5 Tarresque Race (Petite Paragon, PEACH)

[Metastachydium]

Hey, Ripptor! Long time, no see.

Armor Class:20 (+2 Armor, +3 Dex, +4 Natural, +1 Dodge), touch 14, flat-footed 17

This doesn't look right. DEX should be +1 and the Monk-style WIS to AC is untyped, rather than dodge (not to mention that dodge bonuses to AC are lost when a creature is flat-footed). Am I missing something here?

Weapon Finesse[B], Iron Will[B], Endurance[B], Track[B], Imp. Natural Attack(All)[B], Imp. Unarmed Strike[B], Barbed Stinger, Snap Kick

10 bonus feats is a lot. It's clunky, even by 3.5 standards. I'd recommend ditching the five INAtts (there's no fast rule for how much damage a natural attack can deal, after all) and IUS, giving the thing, say, a slam attack instead of the unarmed strike.

It's also missing a regular feat.

Challenge Rating: 6

Yeah, no. Even if we use the build it's meant to replicate as a benchmark, we are looking at a CR of 8 (5 from classes plus 3 from templates (entomanthrope and half-minotaur; the latter being notoriously under-CRed)) or so and I could argue for a value higher yet.

Level Adjustment: +2

Again, I don't think so, no. With werescorpion and half-minotaur alone, we'd have a +3, and that's before stuff like regeneration and the nine immunities (including a few that, NB, the actual tarrasque doesn't even have) some of which are very strong. You see, this is ultimately an issue of methodology.

Let's take a look at trolls, a CR 5, 6 HD Large monster with regeneration and natural attacks. It only has a standard issue 30' land speed (which is low for its size, in fact), a claw-claw bite routine for no more than 3d8+2.5×STR if it spends all its feats on INAtt (no bonus feats), size penalties, no SA other than a boring rend, mostly mediocre SQs and an awful creature Type. Its NA is one higher than the little tarrasque's and its regeneration is slightly better, but it's otherwise inferior in every possible respect.

Despite that, its official LA is a +5. Now,
1. WotC LAs are stupid for sure, we are in agreement there, but RLA is essentially a homebrewn alternative system. Most homebrewers who assign RLA to their monsters list it separately from the WotC-style one;
2. trolls have an RLA of +0. A creature with 6 RHD and an RLA of +2 would be the cloaker. Is the cloaker on par with this? I'm not sure. Is there a class that could turn the troll into something as strong at this in a mere two levels? I highly doubt it.

Dungeonbred Half-Minotaur Lesser Tiefling

Quick question: how does that even work? A Half-Minotaur Lesser tiefling is a humanoid and not even entomanthrope actually changes that; as such it cannot have the dungeonbred template by RAW.