Mo Willems (b. 1968) is an animator and writer who has worked in both capacities on Sesame Street, and designed and directed the opening for "Elmo's World". As a writer, Willems contributed scripts from Season 24 through Season 33 (2002). He created and animated the many cartoon segments starring Suzie Kabloozie, as well as other spots, and wrote and directed the home video release The Alphabet Jungle Game.
In a 2010 interview, Willems remembered getting hired at Sesame Street:
“When I got there I was making films for grown-ups. I was really happy to get the job because it paid the rent and I was getting to write sketch comedy. That's what Sesame Street is. It was at Sesame Street that I learned how to write for children. I wrote a lot of Elmo and a character called Baby Bear. By the time I was gone I realized this was where I wanted my career to be.”
Outside of Sesame Street, Willems created the Cartoon Network series Sheep in the Big City (which at various times featured Sesame Street cast members Joey Mazzarino, Stephanie D'Abruzzo, Fran Brill, Ruth Buzzi and Jerry Nelson). He also wrote for Codename: Kids Next Door and created the "Off-Beats" interstitials for Nickelodeon.
More recently, Willems has shifted to writing and illustrating children's books, including Don't Let the Pigeon Drive the Bus, Knuffle Bunny: A Cautionary Tale, and Leonardo the Terrible Monster.