Jef Czekaj is a cartoonist, children's book author and illustrator, musician, and hip hop DJ who lives and works in Somerville. Running in English and Spanish in Nickelodeon Magazine for more than ten years, his adventure comic strip, Grandpa and Julie: Shark Hunters, is read by over a million children each month. He is the co-founder of The Somerville Comics Collaborative and is a founding member of the Handstand Command music collective. Four of his books--Hip and Hop, Don't Stop!; Cat Secrets; The Circulatory Story; and Yes, Yes, Yaul!--have been Junior Library Guild selections. Cat Secrets was a finalist in GoodReads Best Books of 2011, and A Call for a New Alphabet was called a "Must-Read" book by the Massachusetts Center for the Book.