Many siphonophores are long and string-like, but some, like the venomous Portuguese man o'war (Physalia physalis), resemble jellyfish. Although a siphonophore may look like a single animal ...

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 ...