Americans are expected to spend a record $9.1 billion on Halloween this year — and that's not just on kiddie costumes, candy and decorations.

It might seem like all fun and games: but the business of pet Halloween is no joke. The National Retail Federation recently estimated 16 percent of Americans plan to dress their pets in Halloween costumes this year, spending around $440 million on a trend that's expected to continue growing in popularity.

This year's spending is a nearly 5 percent jump from 2016's $420 million and has doubled since 2010, when the NRF first began asking about pet costumes.

Thanks to traditional pet supply stores like Petco, as well as Amazon and Etsy, the costume choices are limitless: Consumers are dressing their pets up as pumpkins, food, other animals and even superheroes.

Spending nearly half a billion dollars on animal costumes might sound over the top. Yet the amount of time, energy and money people are willing to spend on doggie dress-up was on full display recently at the 27th annual Tompkins Square Halloween Dog Parade in New York.

The highlight of the event — which was held Oct. 21 and attracted 25,000 spectators — is a catwalk where dogs (and their often equally dressed-up owners) show off their costumes in front of judges and revelers.

Costumes of national figures and food were especially popular, with hot dog costumes particularly favored by dachshund owners. These garments typically consisted of one-piece slip-ons that can be found in stores.

One owner said he chose a hot dog look because it was easy to repeat from year to year. His dog Oscar (pictured below) has worn the same outfit for six consecutive Halloweens.