My daughter was fascinated by snails so we kept a large garden snail for a few days. I modeled this from photos after we released it back to our garden.
Several options are available:
Low poly base model
High poly (subdivided) model
High poly model with body and shell as separate pieces
Good support generation and part cooling needed. Scale to 150% for less delicate antennae. I added a manual support version which greatly improved the print quality for me, but the support is difficult to remove.