In Krystle Gould’s fifth-grade classroom at Crescent Park Elementary School, there’s no room under her desk — it’s packed with 11 inflatable dinosaur costumes.

“It came down to ‘Harry Potter’ and ‘Jurassic Park,'” said Gould, who with her class will lead the Bethel Halloween Parade through town Oct. 31. Her past classes have marched as dalmatians (with Gould as Cruella DeVille), Minions and characters from “Willy Wonka.”

Each year, students brainstorm costume ideas, vote on a theme, then keep the final choice secret from the rest of the school and the Bethel community — who line Main Street to watch the annual Halloween parade.

This year, they’ll be dinosaurs, and Gould will be Ellie Sattler, the paleobotanist from the popular “Jurassic Park” film. Her students will be raptors and T-rexes in assorted colors. Alia Sabins will have a custom “Jurassic Park”–themed costume that wraps around her wheelchair.

On Oct. 14, the students excitedly raised their hands to share ideas that didn’t make the cut.

Clara Chase suggested Gould dress as a Sephora employee. The girls would be customers at the cosmetics’ store and the boys could be “the dads.”

“It’s fifth grade,” Gould reminds.

Other ideas tossed around this year included “Harry Potter,” “Toy Story,” Taylor Swift, a sled dog team and library books with Gould as the librarian. Marli Sullivan pitched Gould — a Celtics fan — as the coach of the NBA team, with the fifth graders as fans.

The students are responsible for researching costumes within a set budget, factoring in the number of students and the cost of accessories. Gould said some compromises are often necessary — skipping one costume element to afford another.

Gould, a Bethel native, teaches in the same classroom where she was a fifth grader. She remembers marching in the Halloween parade. Her go-to costume was a witch, though once she went as a clown.

“Being a fifth grader, you get to lead the parade. It’s a special moment,” she said.

Now in her fourth year organizing themed costumes, Gould said it has has gotten easier — in part because parents are eager to help. Last year, when the students couldn’t afford wigs for their “Willy Wonka” theme, one child’s parents stepped in and ordered them for the class.

The group costume tradition started during Gould’s first year, when a few students weren’t planning to dress up. She thought more might participate if it felt like a team effort. One holdout brought in an inflatable dinosaur costume, but at the last minute joined his classmates as a dalmatian.

Gould kept that costume in her ideas list. It reemerged this year.

On Halloween, as 11 dinosaurs parade along Main Street, Gould said she will be close behind, with extra batteries in hand, in case one starts to go flat.

Bethel’s Halloween Parade is on Oct. 31 at 1 p.m. It begins on Mason Street, turns left onto Main Street then circles back to school.