A crustacean is something that has a hard shell. This includes crabs and prawns!
Crabs anemone barber-pole Barnacles beady-eyes black black-back black-eyes blotches blue blue bands blue spots blue-eye-stripes box broken-back brown brown-spots bug bug-eyes burgundy coral Coral Crabs Crabs cream daddy-long-legs dart-tail eye-stalks fan feathers green grey hairy head-showing Hermit Crabs horns hump-back Isopods juvenile large-claw lilac Lobsters long-legs Mantis Shrimps mottled olive orange piece-of-rubbish pink pointed-long-arm-shell Prawns purple purple-legs red red-claws red-spots rubbish shells Shrimps speckled speckles spikes spot spots stalks striped-legs stripes translucent transparent warts weed white white body white-pincers white-spots white-stripes yellow yellow-legs yellow-spots