I needed a mouse character for this bit and I thought it'd be fun to bring in an actual canon Baum character for this role. Hickory along with his siblings Dickory & Dock appear in L. Frank Baum's first published children's book, Mother Goose in Prose (1897). In this book, Baum wrote short stories based on public domain nursery rhymes sorta like how I'm writing a graphic novel based on The Marvelous Land of Oz.

I'm depicting the field mice as Munchkins (wearing blue) as that's where they were introduced in the first book. I imagine the Queen might rule mice all over Oz, though.