If for some reason you feel your pet needs to dress up for Halloween, how degrading for the pet, here is the only costume that pet needs in my opinion. A Freddy Krueger costume complete with claw glove. If you are going to subjugate them to a costume, they can at least be a bad-ass movie villain. 

Image Credit: Party City

The Party City online posting's description of the costume might be the best part.

Take your pup on a walk down Elm Street in our Freddy Krueger Dog Costume. The red striped sweater features jagged hem detailing and hook-and-loop closure. The Freddy hat has attached strings that loop around their ears to stay in place all night long. A foam slasher sleeve is comfortable for your pooch as they tear it up this Halloween in our Nightmare on Elm Street dog costume.

I know that the "jagged hem" piece will surely get your pet's attention!

So my wife REALLY enjoys dressing up our pets...annoyingly so. I mention this as I generally lose every argument with my wife over dressing up our pets. Which in the long run doesn't mean much, but it's the premise of it. They have fur and hate the costumes, and the other neighborhood pets I'm pretty sure laugh at them.

There are some other super movie villain costumes if there is no option like in my house. There is a Jason and Beetlejuice.