Cake Urchin (Tripneustes gratilla).
Also known as Cake Sea Urchin, Pin-cushion Urchin, Pincushion Tuxedo Urchin, Tuxedo Urchin, Pincushion Hairy Urchin, Hairy Sea Urchin, Short Spine Sea Urchin, Collector Urchin, Sector Sea Urchin, Gracious Urchin, Priest-hat Urchin, Jewel-case Sea Urchin and Sea Egg.
Found singly or in groups on coral and rocky reefs amongst sand, rubble and in sea grass meadows. Varies in colour from place to place. They feed on invertebrates, sponges and even dead fish. Length - 15cm Depth - 0-25m. Widespread Indo-Pacific.
Cake urchins have a blue, purple to brown body, short white spines sometimes tipped with orange, and brownish-red tube feet. In some years it can be abundant while in other years quite rare. This urchin has a habit of grabbing pieces of seaweed, shell or pebbles with its tube feet and covering itself. This may act as camouflage and protect it from predators and the sun.
Photo by Brian Mayes at Lembeh