25. Pufferfish

They might look like amusing grumpy balloons, but the tetrodoxin venom produced by pufferfish is no laughing matter. Each one carries enough of the stuff to kill 30 people and it’s 1,200 times more poisonous than cyanide. Interestingly, pufferfish is actually a delicacy, but it can be a deadly one if it’s not properly prepared.