Not only is it not a jellyfish, it's not even an "it," but a "they." The Portuguese man-of-war is a siphonophore, an animal made up of a colony of organisms working together. The man-of-war ...

What’s so startling is the size difference: Males are about the ... which it uses to its advantage by yanking the siphonophore’s tentacles off and brandishing them as weapons against predators.