We did the Wizard of Oz theme for Halloween 4 years ago, too! Kennedy was Dorothy and Aubrey was Toto!
Aubrey was just a few months old so I wanted something that would be warm and comfy without a lot of fuss. She wore a gray fleece shirt/pants set. I sewed felt ears to the hoodie and a tail to the back of the pants. And of course cute red ribbons so that people knew this Toto was a girl!
I can't believe my babies are so big now!