Whenever, you're ready, please go ahead and post whatever you think needs revision in the adult Krakentuas.
Let's see, where to begin.
Firstly, its Challenge Rating is too high for the listed stats.
Compare our current 3.5 conversions of the CR 30 Krakentuas (Male & Female) to the CR 28 Reptilian Gargantua.
The Godzilla-expie would slaughter a Krak. A Krakentua has trouble hitting Repto's AC 50 with its +42 to +46 melee attacks and those have to go through its epic DR. I ballpark it'd do about 40 damage per full attack, give or take. None of its special attacks are likely to work, since their DCs are too low compared to the Reptilian's Saves.
That means it'd take a Krakentua 30+ rounds to chip through the Gargantua's hit points.
Contrariwise, the Reptilian Gargantua only needs one critical hit with its +78 bite attack and the Krakentua is basically dead, as its Devastating Critical is DC 63, a full 27 points higher than the toughest Fort Save of the Krakentua, the Male's Fort +36.
Even if it doesn't rolll any bite crits, a Reptilian will simply turn the Krakentua into mincemeat using Power Attack. Its opponent only has AC 16, so the Gargantua can reduce its natural attacks to +15 melee and do around 450 damage per round it full attacks.
Secondly, the original monster doesn't do
that much damage.
A male had seven tentacles that could whip for 1d4, constrict for 1d10, or wield human sized weapons like 1d10 katanas; plus its two colossal fists that punched for 1d10. The female has more powerful tentacles (1d8 whip or 2d6 constrict). That's a range from 49½ potential damage (9d10) if its wielding seven katanas down to a mere 28½ (7d4+2d10) for an unarmed Male with just its tentacles and hands.
That is a LOT less damage than an AD&D Kraken, which can do 80½ (18d6+7d4).
Thirdly, while its Monstrous Compendium entry starts with a declaration that it's "among the most fearsome creatures in all of Kara-Tur" I feel the Krakentua's role is more that of an end boss for a decent high level party's adventure, analogous to a Balor or Pit Fiend, rather than an Impossible Epic Threat like the Reptilian Krakentua was designed to be.
I'd be inclined to redesign it with a target Challenge Rating of 20 or so, with the Female's CR being a notch or two higher.
Would likely make its hands the primary attacks and allow them to wield Colossal scale weapons, but make the tentacles secondary attacks that can only wield weapons up to Medium size, or maybe up to Large for a Female since they're more dangerous than the Male?
Also think it needs a version of the Marilith's "
Feats: In combination with its natural abilities, a marilith’s Multiweapon Fighting feat allows it to attack with all its arms at no penalty."
Like so:
Feats: In combination with its natural abilities, a krakentua’s Multiweapon Fighting feat allow it to attack with all its tentacles at no penalty.
Oh, I'm not sure about
Advancement by Hit Dice and would consider making it By character class, just to open up more interesting possibilities.
Alternatively we could "Epic it up" so its stats and abilities are a better fit to a CR 30 Monster, but I think it'd be more useful trimming its CR down to 20 or thereabouts.
