Well, from what I've seen of food web worksheets that I have given my science students, there was usually a group of animals and plants and they had draw lines connecting the consumers and producers. Remember how how the Crocodile Hunter always called them the "Apex Predator"? That's because there's a lot of webbing going on underneath, but not much preys on alligators/crocodiles.
Crocodilians are found on the top of the food web. As eggs and hatchlings, they have predators such as birds, larger reptiles, and large fish. Larger crocodilians will always prey on smaller ones. As they grow and reach a substantial size, man is their only true predator.
This is a real basic answer, but I hope it helps you with your homework project. Good luck!!