Box Jellyfish No Bigger Than Your Fingernail Can Kill You in The Blink of an Eye

Habitat: mostly Australia but has been found of the coast of Japan and Florida.
Status: Not Evaluted

Aww look at this tiny jelly! The Common Kingslayer (Malo kingi) is only about 5 millimetres (0.20 in) to 25 millimetres (0.98 in) wide (or wider) and has four long tentacles, which can range in length from just a few centimeters up to 1 metre (3.3 ft) in length. Wait. WAIT a sec. Why is it called the common kingslayer? That sounds just a taaaad bit ominous, no?

Well… upon further research, this itty-bitty jelly is so cute it might kill you. No, really. And not from like the sheer adorableness of it… but from its insanely poisonous sting. This species of box jellyfish was described as recently as 2007 after an 44 year-old American tourist by the name of Robert King was swimming in Australian waters and encountered this minute box jellyfish. He was stung and died soon after. That’s where i’s morbid name of ‘Common Kingslayer’ comes from (after Robert King).

So what makes this tiny jellyfish so deadly? Well, it’s a type of Irukandji jellyfish which are able to fire their stingers into their victims, causing symptoms collectively known as Irukandji syndrome. While most jellyfish only have stingers located on their tentacles, the Common Kingslayer and other Irukandji jellyfish have stingers on their bells as well. Once stung, the victim doesn’t feel much except for some moderate irritation. However, the severe symptoms don’t rear their ugly heads until about 5–120 minutes (30 minutes on average). Irukandji syndrome is characterized by severe pains at various parts of the body (typically excruciating muscle cramps in the arms and legs, severe pain in the back and kidneys, a burning sensation of the skin and face), headaches, nausea, restlessness, sweating, vomiting, an increase in heart rate and blood pressure, and last but certainly not least – a psychological  phenomena which consists of a feeling of  impending doom. Currently, there is no anti-venom for these box jellyfish. Only symptoms can be treated, which can last from hours to weeks.

Move over Jamie Lannister – there’s a new Kingslayer in town.