Children’s book publishers across the country held parties as staffers showed off costumes inspired by favorite characters and books, both classic and contemporary. We’ve gathered a selection of photos from the festivities.

First Book’s eCommerce team waged an epic costume battle dressed as the characters and creators of The Legend of Rock Paper Scissors by Drew Daywalt, illustrated by Adam Rex.

Members of Scholastic’s licensing team dressed as characters from J.K. Rowling’s Fantastic Beasts and Where to Find Them.

HarperCollins publicists channeled their inner Jackies and JFKs.

Suzanne Murphy, president and publisher of HarperCollins Children’s Books, paid a costumed tribute to legendary Harper editor Ursula Nordstrom.

Devin MacDonald (l.) and Megan Peace of Scholastic took on the roles of Dav Pilkey’s Dog Man and Cat Kid.

Little, Brown staff members celebrated the Halloween launch of Nevermoor: The Trials of Morrigan Crow by Jessica Townsend.

Disney Publishing's editorial team lit up the office as the Main Street Electrical Parade. (From l.): Rotem Moscovich, Laura Schreiber, Stephanie Lurie, and Heather Crowley.

Simon & Schuster designer Russell Gordon took a page from The Official Mortal Instruments Coloring Book by Cassandra Clare, illustrated by Cassandra Jean.

President and publisher Jon Anderson (l.) and executive assistant Richard Ackoon of Simon & Schuster gave a nod to Peter Reynolds's Creepy Pair of Underwear.

Macmillan’s publicity department dressed as characters from Shannon Hale’s graphic memoir, Real Friends, illustrated by LeUyen Pham.

In celebration of The Joy of Cookies, members of the Imprint team dressed as Cookie Monsters—and a coveted cookie.

Candlewick employees assembled in their festive attire. Can you find Waldo among them?

Candlewick’s subsidiary rights team all live in a yellow submarine.

National Geographic Kids went wild with a jungle-themed costume contest.

The Children’s Book Council’s Early Career Committee and the Association of American Publishers’ Young to Publishing Group hosted a Halloween party at the Slaughtered Lamb in New York City. (From l.): The first-prize winner of the costume contest, Nora Long of Writers House, dressed as a Wild Thing; Hannah Babcock of Abrams was Cloudy with a Chance of Meatballs; and Ellie VandenBerg of Baker Literary Scouting went as Eloise.

The children’s team at Albert Whitman & Company paid homage to Gertrude Chandler Warner’s The Boxcar Children series, which is celebrating 75 years in print.

Rodale Kids celebrated a healthy Halloween with a pumpkin carved with the Rodale logo and fruity hats in tribute to Mrs. Peanuckle’s Fruit Alphabet, illustrated by Jessie Ford.

Holiday House put out a Halloween-themed spread for its celebration.

Workman staffers got in the team spirit. (From l.): Christi Hagemann dressed as Moaning Myrtle from the Harry Potter series, joined by SarahMay Harel and Emily Weldon as Riverdale River Vixens, Andrew Schlager as Jughead from Riverdale, and Jocelynn Pedro as another Riverdale River Vixen.

Chronicle staffers took inspiration from recent titles and products in devising costumes and decor, including this tableau of Shakespearean deaths by the marketing department. So much for “all’s well that ends well.”