Follow that Bird had 2 antagonists... an antagonizing force (Finch), and a duo of villains (The Sleeze Brothers... I count them as one). Each had a connected part to the story... Finch trying to catch Big Bird due to her own self righteousness, The Brothers capturing him for their circus. I could say that would work pretty well in a Muppet film. Either 2 villains or one villain and one pain in the neck antagonist (like I said, a Zenegata character) The thing is, Follow that Bird was pretty much like that. I think it would work well with the Muppets, only slightly changing it up a bit to not exactly resemble both films. Of course, we can have them split into teams to solve a mystery or capture a criminal. So they don't have to recycle the plot line of Mad Mad Mad Mad World exactly.