I want to change the texture of specific objects, making shift across the surface of the object. I don't know how to insert keyframes for UV mapping though.

I want to change the texture of specific objects, making shift across the surface of the object. I don't know how to insert keyframes for UV mapping though. How can I make the image on the object move? Think of a magical cape, with the design constantly flowing on the cloth. How could I achieve something like that?