[Click for larger size.] At Shorpy Historical Photos, which is a wonderful thing on the internet:

1914. "Kittens in costume as bride and groom, being married by third kitten in ecclesiastical garb." Holy catrimony! Photo by Harry W. Frees.

More about Harry Whittier Frees: Wikipedia, here's Shorpy's archives of his work, and Amazon has books of his work.