He’s a bit young yet (8) to be Harry in his first year at Hogwarts (11), but the black hair dye, round glasses, and lightning scar make him look uncannily like a young wizard — he seemed to get a lot of attention while out trick-or-treating.
After reading all the Harry Potter books, Cam decided to go as his new favorite fictional character (Pokémon excepted, perhaps). Ian, after seeing Toy Story 3 twice in the theaters, and after watching the first two films umpteen bazillion times, decided to go as Woody. (Last year, you may recall, he went as Buzz Lightyear, so his interests are pretty consistent.)