I can't remember a name of a book, I may have read it in middle or high school, help me?

This is all that I can remember of the book that is so vivid in my memory as of recent. It was definatly fanasty. It was about a boy who lived on some kind of farm and in this kingdom there was a castle that had a bunch of alligators in the moat surruding the castle. The boy went out in the swamp lands and found a civilization and tried to save them? mabe. I can imagine it taking place in somewhere between an old bible fable tale and the GA swamp. I remember something about a panthar down in the edge of the field and the boy killed it with really good aim. Then it was that he met his friend. Fiennechie? was perhaps the name of the people. Anykind of help would be really great. You know how it goes, you try so hard and you remember it but you can't explain it or remember it's name. Like I said I think I read it in either high school or middle school.