If you're dog isn't quite up to the task of saving humanity from flesh-devouring giants, perhaps you can instead enlist her to sniff out the Rebellion -- and then maybe pee on their X-Wings -- in one of these adorable (and official!) Star Wars costumes.
ThinkGeek has unveiled these perfect Halloween get-ups for the Imperial Stormtrooper lurking in every pooch: the AT-AT Walker, available in a range of sizes, although a Chihuahua would probably look ridiculous in one (then again, we're talking about dog costumes, so "ridiculous" is only a matter of degrees); and, my favorite, the Dewback, complete with mounted Sandtrooper.
Unlike the AT-AT Walker, the Dewback comes in one size only, with very specific parameters (20-inch maximum belly girth?), thus making it unsuitable for my oversize pup, who would probably eat it anyway.
(via Laughing Squid)