Cleon
Legend
The reason I want to stick to 1 tentacle is not just to reduce damage but because we're having them gain tentacle attacks at each size category, so it makes some sense to do that for the baby as well.
I preferred giving them 4 attacks all the way up. We've already had a bunch of "grows more tentacles as size increases" monsters.
Shouldn't the adult only get 2 feats anyway? You can just drop Great Fort.
For some reason I was sure they had 6 Hit Dice...
Oh I see, the original had 4-6 Hit Dice. That suggests it advances by 100-150% and 150-300% HD:
Advancement: 5-6 HD (Medium); 7-12 HD (Large)