In a similar vein, a giant hermit crab (Petrochirus diogenes) sits on top of what, writes Harris, is "probably" an angular sea whip (Pterogorgia anceps), shown above. Pictured above is a colourful ...

While most hermit crabs can grow up to 10 centimeters long, or roughly five times the width of a human thumbnail, giant hermit crabs can grow up to 30 centimeters, or almost a foot long.