It's really, really hard to describe Mr. and Mrs. Bunny - Detectives Extraordinaire! It exists in a nebulous space between Watership Down and MAD Magazine, and if that doesn't sound like a place that's even possible, I probably would have agreed with you before reading it. This is true even though Rachael's initial review of the book gave me as much of a heads-up as it was possible to provide.
And you know what? It's amazing.
Certainly, in terms of the Newbery criteria, Mrs. and Mrs. Bunny truly excels in its characters. From its questionably competent title characters, to the insufferable Mrs. Treaclebunny, to the perennially exasperated Madeline, each personage who appears in the story is impossible to forget. It's similarly exceptional in setting and style.
If you wanted to criticize the book, the place to go might be to the development of plot critereon. Yes, the book has a plot, but it helps not to think too hard about the plausibility of any given event. However, plausibility isn't the point of the book, and it would require a superlative resistance to Horvath's manic charm in order to complain too loudly on that point.
Mrs. and Mrs. Bunny is a weird, weird book, and it might be one that's not all that easy to build consensus around, especially given how notoriously hard it is to generate agreement on humor. But at the same time, it has some of the same magic that's made novels such as The Phantom Tollbooth and Sideways Stories from Wayside School lasting classics. I need to go through the rest of our semifinal list to see exactly where Mr. and Mrs. Bunny places in my final list, but it's certainly a strong and worthy contender, and a book that I'll probably buy for my daughter for Christmas.
If you have any other thoughts, please feel free to share them in the comments!