The word snail is a common name that can be used for almost all members of the molluscan class Gastropoda which have coiled shells in the adult stage. Those snails which do not have a shell or only a very small shell are usually called slugs. Due to its slowness, the snail has traditionally been seen as a symbol of laziness.
William T. Riker referred to an Earth nursery rhyme, "What Are Little Boys Made Of?", which stated: "Girls are made from sugar and spice, boys are made from snips and snails...and puppy dog tails," to describe the "old-fashioned way of looking at the sexes" to the androgynous Soren. (TNG: "The Outcast")
Snails and other such mollusks are Ferengi delicacies. When Nilva visited Deep Space 9 to talk about Grand Nagus Zek's future and females wearing clothes, Zek suggested they discuss the matter over snail steaks. (DS9: "Profit and Lace") Later, when stranded with Odo on a planet, Quark lamented the lack of slugs there, as well as beetles, worms and snails. (DS9: "The Ascent")