How to add a fixed gif image to side of the browser

Hello – I need to add an image to the side of my browser. I am trying to find a plugin that will do this. In this case my image will be a gif.

It is essentially like the fixed ads we often see on sites – that stay in the same position fixed to the left of the browser and stays in position when scrolling.

Does anyone know any plugins like this?

Thanks for the help.