Venomous sea Creature causing max deaths?

The Box Jellyfish (Chironex fleckeri) causes the most deaths among venomous sea creatures, responsible for more fatalities than sharks, crocodiles, and stonefish combined. Their venom causes cardiovascular collapse and can kill within minutes. While pufferfish are poisonous (not venomous), stonefish have painful stings, and blue-ringed octopus have deadly venom, box jellyfish cause the highest number of human fatalities.