Union Square & Co. today announced a new Mo Willems picture book, It’s My Bird-Day!, which will release on March 31, 2026. The 11th picture book to star the Pigeon, it will be accompanied by a birthday-themed licensed title, gift and stationery products from the publisher’s Knock-Knock imprint, YouTube content, and consumer products from Willems’s growing list of licensees.

This is the fourth title in the core picture book series since Union Square & Co. took over publishing duties in January 2022, following The Pigeon Will Ride the Roller Coaster! (2022), Don’t Let the Pigeon Drive the Sleigh! (2023), and Will the Pigeon Graduate? (2025). The company has also released other standalone Mo Willems originals.

In the new title, the Pigeon is excited about his upcoming birthday before discovering that he has to share his big day with others. “He has a classic Pigeon freakout,” said Tracey Keevan, VP and editorial director, Union Square & Co, and Willems’s longtime editor. “It’s also a surprisingly moving book that is subtle but impactful, showing that you can be seen and also a part of something bigger than yourself. There’s an emotional moment when you, the reader, are really empathizing with and understanding the Pigeon.”

This will be the first time Union Square is releasing a complementary licensed book alongside a Pigeon picture book. It’s The Pigeon Party Book! is an 80-page coloring and activity title featuring games, puzzles, gifts, cards, decorations, stickers, and a two-sided pullout poster. Knock Knock’s products, meanwhile, will include color-in cards and wrapping paper kits.

The birthday-themed publishing, as well as the other products and content supporting the new book, are part of an expansion of the Mo Willems brand that has been ongoing since Willems, along with RedBird Capital Partners and Stampede Ventures, launched the Hidden Pigeon Company in early 2023.

“HPC was formed with the singular mission of extending Mo’s properties, based in books, into products, entertainment, experiences, and more books,” said Tori Cook, senior VP, franchise management, at HPC. “The books are tentpoles for us. Even when we’re extending into entertainment, it all has to relate to the heritage in publishing and a love of reading. It all has to tie back to the books.”

In March 2025, Union Square & Co. signed a 10-year deal with HPC expanding its rights to include licensed books as well as gifts and stationery products through Knock Knock. Most of its licensed publishing and products to date have featured the Pigeon, Elephant & Piggie, and Knuffle Bunny. These are not only Willems’s three most popular properties but also have anniversaries coming up—Elephant & Piggie’s 20th in 2027, the Pigeon’s 25th in 2028, and Knuffle Bunny’s 20th in 2029—that will serve as hooks for ancillary publishing and products. The goal is to release about 20 licensed titles per year to supplement the approximately three to four Mo Willems originals published annually.

Union Square’s first licensed title was Don’t Let the Pigeon Color This Book! in October 2024. “We were exploring what it means to be a licensed book in this world,” Keevan said. “We’re really working to have a narrative throughline. We want to elevate the idea of a licensed activity book and keep it at the quality one would expect from Mo’s brand. The books are staying true to the characters, stories, and world, but also adding that element of play.”

On September 2, Union Square published the first-ever Pigeon concept board book, The Pigeon WON’T Count to 10! “It’s hard to believe there’s a new take on a counting book, but this is a classic counting book subverted in the way only the Pigeon can,” Keevan said. It is the first in a series of four titles, set to release every six months or so, with the others focusing on ABCs, shapes, and colors.

This fall also brings a collaborative title, Mo Willems Workshop and Crayola Present: Make Your Mark!, in which the Pigeon and friends experiment with cooking, jewelry making, writing, dancing, art, and more, for a total of more than 100 creative ideas. “It’s a real hands-on look at what creativity means,” she said. The book comes with a pack of two-in-one Crayola Double Doodles markers in the Mo Willems palette, as well as stickers and a double-sided pullout poster with 50 things to do and space for readers to add their own ideas.

These two titles, along with 2019’s The Pigeon HAS to Go to School! and a collection of themed licensed products, were part of a back-to-school marketing effort that also included a YouTube takeover consisting of the Mo Willems Workshop channel being featured on the YouTube Kids home page; a curated playlist of read-aloud and animated versions of themed titles; and the launch of the first-ever localized YouTube video, a read-along version of The Pigeon HAS to Go to School! translated into seven languages.

“Back-to-school will forever be an important part of this brand,” Cook said. “Teachers use the books to teach reading and have kept them in front of new audiences every year for 20-plus years.”

Enhancing the Brand

While Union Square & Co. holds rights to most licensed formats, including 8x8s, readers, storybooks, and coloring and activity formats, “there’s still an opportunity to enhance and bring awareness to the brand with specialty and novelty formats,” said Paula Allen, HPC’s publishing consultant. “Mo has always wanted to incorporate play into his books, and we’re talking to a variety of publishers with unique programs.”

The first licensees to take the property into their proprietary formats are Phidal, the PI Kids imprint of Phoenix International Publications, and the Studio Fun International and Thunder Bay Press imprints of Readerlink’s Printers Row Publishing Group division.

This fall, Phidal is releasing We Are in a Busy Book!, which plays off the Elephant & Piggie title We Are in a Book! and includes a board book, play mat, and toy figures, as well as The Pigeon Wants to Play!, a title in the Tattle Tales format with a board book and figures. In 2026, the Willems characters will appear in other key Phidal formats, including a My First Puzzle Book, a Bath Time Book, and a Read & Doodle.

“We highlight books that are interactive and imaginative, and we share that mission with Mo Willems,” said Karen Soussan, licensing-corporate counsel at Phidal, who noted that when the team met with Willems at Bologna, “the ideas just kept coming and coming.”

Unlike many licensed novelty titles, which tend to be adaptations of existing content, Phidal’s Mo Willems books—and those of the other licensees—will feature brand-new storytelling. “It’s all original, which we don’t often do,” said lead designer Azad Injejikian. “This was special because it’s so in sync with Mo’s mission.”

PI Kids, meanwhile, will publish five titles from summer 2026 through late 2027/early 2028. “Kids and parents love Mo Willems for his unique art style, the humor, and the interactive storytelling,” said Susan Rich Brooke, chief publishing officer. “The characters speak directly to the reader, and our sound and novelty formats can extend that in even more ways.”

The first title, for summer 2026, is a Pigeon Little Music Note Sound Book featuring six songs, and the second, for spring 2027, is a Pigeon version of the company’s Steering Wheel Sound Book. Future titles will include an Elephant & Piggie I’m Ready to Read Sound Book, a Pigeon Little Sound Book, and a newer novelty board book format.

“We’ve been admiring Mo Willems for years,” said John Russell, PI Kids’ VP, global licensing and marketing. “The sound element is a new twist on a classic property and a new way for kids to interact with these characters and stories.”

Studio Fun will launch a new sound book format with the Pigeon in October 2026. “From a brand perspective, the property is a blend of literary prestige and mainstream appeal that aligns perfectly with our licensing strategy,” said Debra Mostow Zakarin, VP and publisher.

“When we first connected with Mo at Bologna he gravitated to our unique formats, especially the 10-button sound books, but he challenged us,” Zakarin continued. “He said he likes to disrupt the norm and asked what we could do that’s different.” That conversation led to the development of Don’t Let The Pigeon Launch the Space Ship!, a sound book featuring a randomizer called the Story Scrambler that produces more than a billion combinations from 10 buttons with 10 sounds each. “It’s a very innovative storybook that’s perfect for the Pigeon because it’s so outside the box.”

Finally, Thunder Bay’s Elephant & Piggie crochet kit, for older fans, is set for a February 2027 release.

HPC’s future plans include more licensed products, expanded YouTube content, traditional entertainment productions, and additional promotional initiatives. “Books are a shared experience, especially Mo’s books,” Cook said. “We look at things kids can experience together with their parents and teachers and see how we can be part of it.”