A pumpkin is always a solid choice for dressing up--so long as you're not the one that's being dressed up.
The animals in all of these costumes look really fed up, which adds to their general brilliance. Look at the first cat particularly closely--that's an animal who is about to use the laundry basket as a litter tray.
Implications - Seasonal events like Halloween present consumers with the opportunity to get extra festive, and this definitely translates into the increasing popularity of pet fashion. As the pet industry continues to grow, products and trends like this will only gain in their widespread popularity which means that this market has a lot of room left for expansion.