In what has become a holiday tradition, several children's book publishers celebrated Halloween this past week in high style, and with some inventive book-inspired costumes. Here, we present party highlights—both spooky and silly—in a holiday tradition of our own: the post-Halloween photo-essay.

At Little, Brown Books for Young Readers, Ames O'Neill (l.) and Jessica Kaufman, dressed as Vampirates from Justin Somper's series, demonstrate why you never want to end up on a publicist's bad side.

Also at Little, Brown, Lisa Sabater (l.) and Trish Hatch dressed as the title characters from Jerry Pinkney's new adaptation of Aesop's The Lion & the Mouse.

LB's Connie Tsu took inspiration from the cover of Happyface, a forthcoming YA novel by Stephen Emond.

Also taking their costumes from an upcoming book, Maria Mercado and Alvina Ling duked it out as Shark vs. Train by Chris Barton and Tom Lichtenheld.

Here, Little, Brown's Andrew Smith showed off his Tintin cowlick, flanked by Tina McIntyre (l.) and Melanie Chang, dressed as twins Ling and Ting from a forthcoming book by Grace Lin.

Don't ask Jill Dembrowski's "Zombie Madeline" about what happened to Miss Clavel.

And Little, Brown's Lisa Ickowitz posed next to her costume's inspiration, Fanny by Holly Hobbie.

Over at Penguin, the second-place winner for most original costume went to this group, who dressed as “Children’s books that should never be published,” which included Strangers Have the Best Candy and Fun with Matches: 101 Hot Ideas. Here, l. to r., are Jill Santopolo, Liz Waniewski, Julia Johnson, Claire Evans, Sarah Davis, Heather Alexander, Andrew Harwell, Katie Carella, and Allison MacDonald.

Penguin’s Puffin imprint won second place for Best Decorated Department. Here, Natalie C. Sousa, Anthony Vernal, Jeanine Henderson, and Kristin Smith showed why.

Puffin also created a haunted house at the Penguin offices; brains were on the menu over at the dining room table.

At Random House, a trio of expert judges — Chip Gibson, Goosebumps author R.L. Stine and Mariella Malloy — decided who would win the publisher's costume contest.

The publicity department took its inspiration from Leo Lionni's Let's Make Rabbits. And who's that hiding in the background? It looks like...

...yes, it's the California Raisins — aka members of the online marketing and editorial team. Here, they posed with R.L. Stine.

The Random House/Golden Books editorial department spoofed Dan Brown covers (including Angels and Donkeys, Are You My Mother, Mona Lisa?, and Horton Heard Too Much).

At Scholastic, publicists Becky Amsel (l.) and Samantha Wolfert dressed as two recent YA heroines: Kelleigh from Pete Hautman's How to Steal a Car and Grace from Maggie Stiefvater's Shiver.

Taking their inspiration from Suzanne Collins’s The Hunger Games and Catching Fire, this group dressed as the 13 districts of Panem. Back row (l. to r.): Fernando Manriquez, Jeff Saline, Gavin Brown, Lauren Szaro, Tori Kosara, Divya Sawhney, and Sheila Marie Everett. Front row (l. to r.): Nicole Corse, Brenda Murray, Amanda Vega, Jacqueline Bernacki, and Stephanie Anderson.

L. to r.: Scholastic’s Rotem Moscovich, Daniel Moreton, Kim Balistreri, and Cecily Kaiser were inspired by Emma Dodd’s Dot and Dash series.

In Scholastic's group costume category, two teams tied for first place. The Magic School Bus team consisted of (l. to r.) Kathleen Donohoe, Jessica Gregorek, Catherine Sisco, Danielle Heimbach, Rafi Mittlefehldt, and Penny Chaiet...

...and dressing as Mr. Popper’s Penguins were, in the back row (l. to r.): Aimee Friedman, Anna Bloom, Matt Ringler, Becky Shapiro, Shannon Penney, Amanda Maciel, and Abby McAden. In front: AnnMarie Harris Anderson, Zack Clark, and Jenne Abramowitz.
Scholastic's Ellie Berger and Alan Smagler came as Princess Potty and Pirate Potty, respectively.

Another costume winner: Jacqueline Harper won as Stick Man, star of the new picture book by Julia Donaldson and Axel Scheffler.

Scholastic's Tracy van Straaten as Stillwater, the serene panda bear from Jon J Muth's Zen Ties.

And no costume party would be complete without some Twilighters. Here, Nick Martin and Nadine Kennedy showed off their best Edward Cullen and Bella Swan.

Meanwhile, at Simon & Schuster Dan Potash won a prize in the individual costume category as "Pancho Potash, illustrator for hire."

But it was S&S's Richard Ackoon who took home the top prize in the individual category for his King of Pop costume.

Jon Anderson dressed as Steve Brixton from The Brixton Brothers: Case of the Case of the Mistaken Identity.

In the group costume category, second place went to the S&S BFYR design department — clockwise from top l., Lizzy Bromley, Krista Vossen, Lucy Cummins, Chloe Foglia, and Laurent Linn — who recreated the cover from Becca Fitzpatrick's Hush, Hush. (And, yes, as might be expected from a design department, there's been some photo alteration here.)

Third place in the group category went to this team of Rhyming Dust Bunnies. Back row (l. to r.): Carol Gottshall, Ariel Colletti, and Anne Zafian. Front row: Chrissy Noh (l.) and Stephanie Hawkins.

S&S Children’s managing editorial department reimagined children’s book characters — from Alice in Wonderland and Little Red Riding Hood to SpongeBob SquarePants and a Karen Katz tot — as vampires. Front row (l. to r.): Christina Solazzo, Bridget McCabe, Dayna Evans, Jenica Nasworthy, Alison Velea, Jeannie Ng, Lauren Forte, and Lisa Donovan. Back row (l. to r.): Amy Bartram, Dorothy Gribbin, Christine Marshall, Craig Adams, and Amy Currier.