From Wikipedia - The siphonophores, are an order of the Hydrozoa, a class of marine invertebrates belonging to the phylum Cnidaria. Although a siphonophore appears to be a single organism, each specimen is actually a colony composed of many individual animals. Some siphonophores superficially resemble jellyfish, like the dangerous Portuguese Man o' War (Physalia physalis). With a body length of 40–50 m, another species of siphonophore, Praya dubia, is one of the longest animals in the world.
Mahi Mahi (Coryphaena hippurus) - I generally don't care about what animals look life if they're tasty but I don't think I'll ever eat mahi-mahi. Some things are too beautiful to kill. (Pigs and cows can suck it.)