For this one I have worked the spiral structure of the shell. It is actually a real spiral, not a fake one! The rest of the animal was done rapidly without consideration for realism. I shall construct a refined model later.
About this creation
Here is the "wild" model
We can see the branchiae in red.
And this is the "tamed" model, piloted by a very "not enjoying the beauties of marine life" kind of guy!