I really really want more creative online modes. There is a lot of possibilities.
Off the top of my head, a mode where one team is stuck as squids, the other humanoid form. The squids have to outsurvive them maybe, idk. I just think that concept has a lot of potential. Reminds me of the Nintendo Land minigames like Luigi's Ghost Mansion and the Anjmal Crossing one.
And glow in the dark ink on some nighttime levels would be sick! And yeah I agree with everyone saying more hairstyles would be cool. High tentacle ponytails, flopped over in the front like bangs, braided, there could be some cool goofy stuff.