Here's a picture of the wall while I'm thinking. I've remembered some pictures of jellyfish that I took at the Monterey aquarium, and those images are what's driving me now.
And here are some of those inspiring pictures!
You can see I've found all my fabrics that might be "ocean" and put them on the right, and have also found the ones that might make good arms, and put them on the the left.
I decided that technically, the way I want to piece this from now on will involve an inner unit (the spiral, as it is pieced so far), and an outer unit (which I'm thinking of as ocean). In this picture, hopefully you can see the row of pins where the outer and inner sections meet. They are not sewn together, and later I will separate the two so I can add the tentacles to the outer section before I sew the two sections together.