What secrets about snails are they keeping from us?

A medieval-style illustration shows three armored figures, two wielding swords and one pulling a rope, confronting a giant snail on a castle wall. The snail has a human-like face and is depicted as a formidable opponent. The overlaid text reads: 'Something that legitimately fascinates me is the sheer number of medieval artworks depicting giant, oftentimes murderous snails'.