Sharks get the headlines, yet several quiet killers on this list are smaller than a hand and far harder to spot.
1Box JellyfishAn Australian jellyfish whose sting can kill a swimmer within minutes.1000pts
2Irukandji JellyfishA fingernail-sized jellyfish whose sting triggers severe, sometimes fatal reactions.584pts
3OrcaA top predator of the sea with no confirmed fatal attack on a human in the wild.515pts
4Reef StonefishThe most venomous fish, easily stepped on in shallow tropical water.515pts
5Oceanic Whitetip SharkAn open-ocean shark notorious for attacks on shipwreck survivors.515pts
6Beaked Sea SnakeA highly venomous sea snake blamed for most sea snake deaths among fishermen.454pts
7Great White SharkResponsible for more recorded unprovoked bites on people than any other shark.384pts
8Bull SharkA shallow-water shark that swims up rivers and shares beaches with people.384pts
9Blue-Ringed OctopusA tiny octopus whose painless bite carries a paralysing neurotoxin with no antidote.384pts
10Geographic Cone SnailA beautiful shell that fires a venomous harpoon capable of killing a person.384pts
11Portuguese Man o' WarA drifting colony whose long tentacles cause intensely painful stings.384pts
12Short-Tail StingrayA huge stingray whose barbed tail can cause fatal wounds.303pts
13Red LionfishA striking reef fish with venomous spines that cause painful injuries.303pts
14Tiger SharkA large tropical shark with a long record of bites on swimmers and surfers.303pts
15Saltwater CrocodileA coastal ambush predator that kills people across northern Australia and Southeast Asia.206pts
16PufferfishA fish packed with tetrodotoxin, deadly when its flesh is prepared wrongly.206pts
