If you have My Penguin on your iPad, check it out! There should be a special temporary Halloween theme in the app, no app updating needed. The theme is on the main page when you first open it up. Check it out:
What a very cool and unexpected touch! Thanks to Dman10297 for letting me use his pictures.
It’s also worth mentioning that the sports catalogue is unavailable at the Stadium during the Halloween Party so you’ll have to use the My Penguin app to get any items from that catalogue for the time being. Thanks Loo978!