Malo kingi or the common kingslayer is an Irukandji jellyfish named after victim Robert King, a tourist from the United States swimming off Port Douglas, Queensland, who died from its sting. It was first described to science in 2007, and is one of four species in genus Malo. It has some of the world's most potent venom, even though it is no bigger than a human thumbnail. As an Irukandji, it can cause Irukandji syndrome, characterized by severe pain, vomiting, and rapid rise in blood pressure.