Description

Also known as Bonnet Snail, Giant Cassis Cornuta, Giant Helmet, Giant Horned Helmet Conch, Hawaiian Helmet Shell, Helmet Seashell, Helmet Shell, Horned Helmet, Horned Helmet Shell.

Found singly or in colonies, on sandy bottoms, sometimes half buried in the sand.
They feed on the crown-of-thorns sea star - Acanthaster planci and other sea stars.
Length - 36cm
Depth - 2-30m
Widespread Indo-Pacific

These shells are hunted for both food and a decorative item, although the Queensland government has put it under strict protection because it hunt the crown-of-thorns sea star.

Cassidae can grow very large and their shells resemble Roman Helmets. These are sand dwellers mainly hunting sea urchins such as sand dollars, using chemicals to penetrate through the hard case via the anus or by drilling a hole.
Ref: https://en.wikipedia.org/wiki/Cassis_cornuta