Box jellyfish with a small fish caught in one of its tentacles. Despite the fish's best efforts at escape, the jellyfish ensnares it in more of its venomous tentacles, to be digested later. Box jellyfish are one of the most venomous animals on Earth, and their stings have caused dozens of human deaths. Despite appearances, box jellyfish (class Cubozoa) are not true jellyfish (class Scyphozoa). Unlike true jellyfish they have true eyes, and they are active hunters. They target and swim towards their prey, rather than drifting as true jellyfish do. As their name implies, their bell is shaped like a box or cube, with groups of tentacles on the rear corners. Filmed in the Gulf of Thailand.