If you’ve ever watched someone in a cartoon walking, you’ve probably notice that the walk repeats itself exactly. That’s because animators make their characters walk using a walk cycle, a set of images that cover the basics of a walk.
There’s a great tutorial about walk cycles at angryanimator.com. If you are planning on creating a walk cycle, I highly recommend going there and finding out how to create each frame.
Here’s the illustration of the walk cycle from angryanimator:
And here’s another, simpler version. It starts with the other leg first, but it works exactly the same way:
And it works pretty well:
Notice that the head and body only change in height, and that the arm is the same image with a slight transform to make it swing.
If you combine a walk cycle with a seamless background, you can make someone walk forever!