I mostly just invented it, there isn’t much reference out there for it since in canon they never show their mouths, but the kasatha in our campaign are more non-traditional. We invented a ton of headcanons for them that apply to the canon of kasatha in our Starfinder campaign.
I more or less headcanon them as having weird shark/squid-based biology, or that’s what it was inspired by mostly anyway. Also like in the above image they have a “primal rage” type thing they can enter that boosts stats and stuff, which I detail a bit here.
There’s only a few things from the canon of Kasatha in the official lore that we borrowed, most of it is made up. As for Noc’s planet specifically, here’s some of the notes I have on it. We refer to it fondly as Space Australia because of the stigma that australian wildlife is terrifying and is all trying to kill you, which is exactly the case on Iropa.
Their society in general is very warrior poet-esque. They value combat traditions and, like in Paizo’s canon, prefer melee combat, touting ranged as cowardly. With their +2 STR and -2 INT they tend to be kinda meat-headed, the non-combat oriented kasatha tend to become seers and such for Shaasa’yaan, their patron deity, who is the god of dreams and storytelling, seer of Truth.
There’s a bunch of other headcanons and lore and stuff, which will be revealed when the podcast for Sovereign-1 eventually drops. Thankfully we have a whole mini-arc on Iropa which is super fun, and we learn a lot about the Kasathan culture that we manufactured.