Published in July 2018, "Why We Went Extinct." became an instant hit. This popular picture book series features animals that went extinct for surprising reasons, such as "Platybelodon, who went extinct because its jaw was too heavy" and "Opabinia, who went extinct because it was too decorated," with the animals themselves explaining their reasons for extinction. The second volume, "More Why We Went Extinct.", was released in 2019, the third volume, "Even More Why We Went Extinct.", in 2020, and the first picture book in the series, "We Went Extinct for a Reason, But We're Amazing.", was released in the summer of 2022. The series has sold over 960,000 copies, making it a bestseller.