Ideas for concept pitch

Ok so I have a few ideas for my concept pitch. I have been looking around at different cartoons and even the little cartoons in the newspaper to gather some inspiration. My first idea, which I will probably run with, is a short story based around a cat that is addicted to cat nip & has resorted to a life of crime to pay for the addiction. I have a few ideas although I am stuck for an ending. The story so far includes a cow named 'Hedge' who runs her own milk production business. In which the cat (who I will now name Pedro!!!) hates the success that Hedge has and steals milk off her to pay for the addiction. This is all sounding a bit scrachy now, but just need to work on my characters and the story line. Right now I have enough ideas to make a feature film!