What is deadlier box jellyfish or blue ringed octopus?

It may be hard to say, but it depends on the type of the jellyfish. A box jellyfish or a portuguese man of war has slightly more powerful toxic than blue ringed octopuses. Portuguese man of wars poison is very painful that it can even cause shock, fever, and lung and heart problems. Other jellyfishes like the giant jellyfish, no. The box jellyfish's venom can easily stop heart and systems functioning. But it is very weird how a lot of people say that blue ringed octopuses poison is strong enough to kill twenty to forty fully-grown humans at a time.