Stephen T. Asma, a professor of philosophy at Columbia College, took up monsters by way of natural history museums, the subject of his last book, where he found “anything from pickled fetuses in jars to bizarre twinning, things with two heads.” His latest book, On Monsters: An Unnatural History of Our Worst Fears, takes on a subject timely not just because of Halloween, but also because of the vampires and zombies appearing everywhere in popular culture. “Vampires are always sort of charming and upper class, and they’re kind of hot,” Asma said, explaining our dual fascination. “Zombies really represent the lowest common denominator. We’re in the middle of these two classes — we have bourgouis desires to be vampires, and we want to avoid the proletarian monsters, the zombies.” Below, he analyzes for Zócalo some lesser-known monsters and monster myths, and explains why we’re still afraid.