Sea snake venom contains a protein that inhibits cellular receptors, leading to organ shutdown, asphyxiation, and cardiac arrest.

“what it does is it has a tiny little protein that binds onto the receptors that tell the cells what to do and that protein dissolves and disappears shortly after the animal dies so basically you have this big giant animal whatever it happens to be a fish a shark a Marine Mammal whatever it is a human and if the snake a sea snake bites you that protein receptor or that protein goes in and stops The Binding agent and so basically your organs just shut down so you'll just be cruising along swimming along whatever happens to be and all of a sudden you asphyxiate to death your heart stops pumping and you just sort of roll over dead in an incredibly painful way”