Many animals defend themselves by mimicking something distasteful, like a wasp or a venomous snake. But the mimic octopus can don a multitude of disguises. It becomes a sea-snake by pushing six arms down a hole and waving the other two around in a sinuous wriggle. It turns into a flatfish by folding its arms back into a leaf shape and undulating them up and down. Its repertoire of venomous animals potentially includes lionfish, sea anemones, jellyfish, and more. It is one of the most dynamic mimics in the animal kingdom.

And now, the mimic has been mimicked.

Last July, while diving in Indonesian waters, Godehard Kopp saw a black-marble jawfish hanging around a mimic octopus. The little fish perfectly matched the