Cleon
Legend
With 22 HD, I don't know if they need turn resistance (nightshades don't have it), but we did give the sea bonze +4. How about +2 turn resistance?
Give them improved grab and constrict, and I'd say they're about the same as the CR 12 kraken. As is, they're probably a tough 11 or a weak 12.
Common?
The rest seems good.
I'm feeling Challenge Rating 11.
I'd be tempted not to give them a weight, since neither a Kraken or Giant Squid has one and I still imagine Umibozu as being half-ephemeral spirit beings.
I'd like to expand the languages a bit - Aquan, Common and Infernal?