TIL about an Australian jellyfish that causes Irukandji syndrome: excruciating muscle cramps, severe pain in the back and kidneys, a burning sensation of the skin and face, headaches, nausea, restlessness, sweating, vomiting, and psychological phenomena such as the feeling of impending doom.
https://en.wikipedia.org/wiki/Irukandji_jellyfish?wprov=sfti1
