Stinky, by Eleanor Davis (2008), is written very well and really grabbed my attention!
The illustrations are very good and they tell you the life you might find in a swamp. This book is part comic part chapter book and it's very easy to read. The problem is a boy, named Nick, comes into the swamp and Stinky Seymour, a monster who lives in the swamp, does not like kids. Solution: Stinky made friends with Nick and Stinky tried an apple and he offered Nick a pickled onion.
I recommend this for ages 5 and up.