The Poptropica Store has some really sweet new costumes that you can get just in time for Halloween. They each cost 75 credits, so if you still have some islands to do you can get them done and have enough credits for the costumes!
Both boy and girl characters can buy the Pumpkin Head costume, which features a cool jack-o-lantern head and a black outfit with green pumpkin vines on it.
Boys can also get the Frankenstein outfit. I think this is my favorite one.
Girls can also get the Bride of Frankenstein outfit.
Plus if you hang out in any of the multiplayer rooms you’ll see people wearing all kinds of other Halloween costumes or bits and pieces of costumes they found around Poptropica using the Costumizer feature. Some of the costumes you can see are really creative!