Chiropsalmus quadrumanus
Chiropsalmus quadrumanus, commonly known as the four-handed box jellyfish, is a species of box jellyfish found in the western Atlantic Ocean, the Gulf of Mexico and the Pacific Ocean. The sting is venomous and dangerous to humans, especially children.
Fitzroy Island National Park
It is unlikely that box jellyfish would be encountered at Fitzroy Island due to the 4 km passage between the island and the mainland, but they have been found there occasionally, as well as other stinging jellyfish.