This is a mug shaped like an Argonaut, a type of octopus that has its own Nautilus-like shell.

From Tiki Shark:

"A limited edition of only 113 Signed Tiki-Mugs will be offered – Packaged in a Hand-Made Natural-Wood crate this Mug's a 'must have' for collectors.

Created in 'Pastel Coral' & 'Ocean Purple' a limited edition of 113 of each color will be offered. Delivery is mid to end of September. Don’t miss out! Limit of only one set per customer, please.

Material – Handmade Ceramic Capacity – 15 oz. Color – Ocean Purple

Each mug will be signed. Comes with a Certificate of Authenticity, Plus a wooden custom-sized crate for display."