But you don't have to spend big bucks. We found a few ways to create some inexpensive options for your four-legged friends.
"We do have a lot of people that come in and their dogs are their kids, and we do have some that come in and make a family costume out of everything," said Amy Rivera with Petco.
PHOTOS: Show off your pets in costume
At Petco's Halloween Bootique, the costumes run the gamut, and cover every pet in the house.
"We have cat costumes. We have tutus for guinea pigs and rabbits and ferrets," Rivera said.
From the furry rodents to the largest of dogs, everyone will get to take part in the festivities, but you must act fast for the best deals.
"If you have a big dog, those costumes go fast," Rivera said.
At Petco, costumes start at $4.99, and you can take an additional 20 percent off selected items with their Loyalty Rewards program.
We also checked out the selection at the Dollar Tree and found kids costumes with work for cats and dogs as well.
Tutus in a variety of colors for medium size pets can be paired with a set of wings, and will make their fairy "tail" come true. If you have a devil of a dog, there are horns and a tail that will make your pet the best in show.
If you want to go the DIY route, there are no shortage of ideas on Pinterest.
When you head out on Halloween night with your dressed up pup in tow, just keep in mind that you should bring your own pet treats along for the adventure.
"You always want to remember that the candy and chocolate is not good for your pet. A little bit of chocolate can be detrimental to your dog's health," Rivera said.