Ranging from the size of a hamster to that of a dog, these gastropods are kept as guard animals by mer-people; but they're just as happy to serve the alien Teuthids. Unlike their garden-variety cousins, their skin is leathery and studded; yet they can still find a chink in plate armor and push their mouths inside to eat the wearer. If overwhelmed, they can pull their bodies into iron shells and become nearly invulnerable. Their scooped-out shells can be used as make-shift shields in a pinch, though heavy. Instinct: Consume flesh slowly

• Insert head and mouth into someone's weak point
• Retreat into iron shell
• Menace someone by advancing slowly