Puffer fish are some very unusual animals. When these odd marine creatures sense danger, they can inflate their bodies three times their normal size to look bigger and scarier. You might not guess it from looking at them, but puffer fish are deadly, poisonous carnivores! Only the poison dart frog has deadlier poison. Sometimes people are poisoned when they eat puffer fish, which are a delicacy in some parts of the world. Readers will be amazed when they dive into this fascinating guide to one of deadliest animals on Earth.