Simon starts with a dramatic report, which he then reveals ""couldn't possibly be true,"" of a black mambo overtaking two galloping horses and killing both the horses and the children riding them. He goes into poisonous snakes' appearance and distribution by way of debunking other fallacious beliefs, which injects some life into the descriptive material, and then on to the business of venom glands, fangs, and the effects of snakebites, topics that are lure enough in themselves. Most of the book is a sharp but unsensationalized review of the world's poisonous snakes, from Asia's deadly, 14-foot king cobra to the pygmy rattler, a small rattlesnake whose bite is ""only slightly poisonous"" and whose sound is ""only a high-pitched buzz."" Finally, he makes clear that though snakes are responsible for more deaths than all other dangerous animals in the world combined, they are needed to control the rodent population. And, on a continent with fewer than a thousand bites and only ten deaths a year, ""for you to worry about being bitten by a poisonous snake just doesn't make sense. . . . There is a higher chance of being struck by lightning."" Downey's drawings haven't the drawing power of other snake-book illustrations, but the text and subject should hook readers.