I have been designing a set of top-down sprites to be used in Scratch 2.0 and 3.0 for games, storytelling and simulation projects. Many have multiple costumes to allow simple animation. If you right-click or shift-click on a sprite on the stage you can export it for use in your own projects.
All sprites and backdrops are designed in Scratch and are Creative Commons licensed (you may use them any way you wish in Scratch or any other application).