The pet costume is the real highlight of Halloween. Not the candy, not the decorations, not even the costume you spent three weeks planning. The moment someone walks through the door with a dog dressed as a hot dog or a cat stuffed into a tiny shark suit, the entire party stops and every phone comes out simultaneously.
Pets have absolutely no idea what Halloween is, no concept of why this is happening to them, and zero ability to consent to any of it, and yet somehow they pull off every costume with a dignity that most humans can only dream of achieving. Whether your dog is a willing participant who struts around like they were born for this or a cat who is plotting revenge from inside a pumpkin outfit, this list has the costume that was made for them. Fair warning though, once you find the right one, you are going to be thinking about next year before October is even over.