Crazy Like a Fox: A Simile Story by Loreen Leedy
This is definitely a one subject book. A fox chases a sheep around which is described with similes until she arrives at her surprise party. There is the larger story and then the commentary (also in simile) that goes on around it by the characters that are observing the chase scene. This would be a good book to use with elementary school students who are studying simile or for English Language Learner Adults - who often have a lot of problems with similes and metaphors. Loreen Leedy's website has the entire list of similes used available to use in a classroom setting.
The illustrations are quirky and colorful - according to Loreen Leedy's website they were drawn and colored on the computer. I didn't like them much, they have that sort of "hip" look that seems to be trying too hard to be cool. But that's me and I am a grumpy adult and not a kid, who probably would like the illustrations just fine.