Horrid Henry and the Zombie Vampire is a later installment (Book 20) in the highly successful series, proving Henry's enduring appeal by tackling contemporary, high-interest themes of monsters and the supernatural. The book contains four new short stories, with the titular tale likely revolving around Henry's attempt to use the concept of a "Zombie Vampire" for his own gain—perhaps to scare Peter, win a costume contest, or get out of homework. The humor comes from the clash between Henry's extreme imagination and the reality of his school and family life. The book is characterized by Simon's sharp wit and Henry's utterly self-centered, hilarious perspective. The inclusion of current monster tropes keeps the series fresh, ensuring Henry remains the ultimate anti-hero for children who enjoy a dose of rebellion and chaos in their reading material.