I hate WCF setup with endpoints, behaviors etc. I believe all these things should be performed automatically. All I want to do is to return JSON result from my WCF service. Here
Take a look at this SO question.
Edit: Since you're not specifying an address for your service, try hitting: http://localhost:22059/ZombieService.svc/KnownZombies (with the .svc).
I also think you need the
behavior added to your specified endpoint behavior.
Edit: Try changing your endpoint definition to this: