This is kinda tough. I could see Bloo wanting the greatest costume ever but ends up just haveing a white sheet with eye-holes.
And Edwardo? I think he'd be too busy hideing somewhere. Duches? Hmm... I think she would feel that Halloween was beneath her. But she'd be the scaryest looking one anyway.
I don't know what Frankie would dress up as. The Little Mermaid idea is great. The green fishtail and red hair would certanly be similar, but differant from her usual get-up. I could see her dressing up like a ball-room bell complete with the mask-on-a-stick. (With a green dress, ofcourse)
I can't see Madam Foster and Mr.Hariman not sharing a theme. Maybe something like Hariman as King-kong and Madam Foster as Fay Wray. But SOMEONE would have to dress up like a character from the Powerpuff Girls. Actually... Mr.Hariman could be the Mayore and Madam Foster could be Miss Bellom.
