Gretch is a prolific children's author, poet, illustrator, and cartoonist. He is best known for his whimsical rhyming poetry, often featuring fictional stuffed species of his own invention. He has published dozens of books, including The Stuffed Cat is a Hat, and One Stitch, Two Stitch, Red Stitch, Blue Stitch, a semi-autobiographical memoir about his trip to the SA emergency room after suffering a seam rip while on a book tour in Europe.