[dissentowner]

I'll go with death by Blue Ringed Octopus.
http://en.wikipedia.org/wiki/Blue-ringed_octopus

The blue-ringed octopus is 12 to 20 cm (5 to 8 in), but its venom is powerful enough to kill humans. No blue-ringed octopus antivenom is available.
The octopus produces venom containing tetrodotoxin, 5-hydroxytryptamine, hyaluronidase, tyramine, histamine, tryptamine, octopamine, taurine, acetylcholine, and dopamine. The major neurotoxin component of blue-ringed octopus venom was originally known as 'maculotoxin', but was later found to be identical to tetrodotoxin,[4] a neurotoxin also found in pufferfish that is 10,000 times more toxic than cyanide.[5] Tetrodotoxin blocks sodium channels, causing motor paralysis and respiratory arrest within minutes of exposure, leading to cardiac arrest due to a lack of oxygen. The toxin is produced by bacteria in the salivary glands of the octopus.[6] Their venom can result in nausea, respiratory arrest, heart failure, severe and sometimes total paralysis, and blindness, and can lead to death within minutes if not treated. Death is usually from suffocation due to lack of oxygen to the brain.