I’d been noticing monsters everywhere. It was 2025 and President Donald Trump had been calling immigrants “monsters.” His opponents hurled the term right back at him. Monsters appeared at the movies, from Sinners to Frankenstein , and on the radio, from Lady Gaga’s “The Beast” to the chart-topping songs from KPop Demon Hunters . My three-year-old daughter was terrified and fascinated by monsters. She pulled a pair of tights over her head and pretended to be a monster during the day, then at night asked me to check for monsters in the wall, before wondering: “What is a monster?” I realized I had no idea how to answer.

So I started reading about monster studies, a niche academic field, and became bewitched by Michael Chemers, director of the Center for Monster Studies at UC Santa Cruz. I called him to ask how he defined monsters and why they seemed to be everywhere.…