The molinillo is a traditional Mexican kitchen utensil, that has been used for centuries to make froth in hot chocolate. It is made of a single piece of wood. The top part, typically thick and round, has decorations and indentations. A number of loose, movable rings follow. Lastly a round handle that is soft and round making it easy to beat with your hands. All of the decorations, shapes and pieces are made to create the most froth possible.

Here is a photo, of mine....


Though it is not that easy to find molinillos outside of Mexico, any market in any part of Mexico will likely have not only one, but different kinds to choose from...