Once Upon A Toy in Disney Springs is located in The Marketplace. This store carries a large assortment of toys and games and features interactive play stations. The back half of the store is devoted to Star Wars. You can build your own Lightsaber or Droid.
My favorite souvenir is customizable Mr. Potato Head. You can purchase as many pieces as you can fit in your container. Make sure you either bring a potato head with you or fill the inside of the one you purchase at Disney Springs with pieces.