Sound and Shaking Pop Up Greeting Card Vietnam Manufacturer, Supplier, Wholesaler. These are unique or funny greeting cards. When opened, they immediately start playing a funny, giggling, or embarrassing song, while shaking or moving in your hand. They are usually battery-operated and will stop after a few seconds or when closed. Some popular types include animal-shaped rattle birthday cards or unique funny cards. You can find them on platforms like Amazon or through professional gift makers like the3dcards.