How can I scare my cat in a harmless and playful way?

One way to scare your cat in a harmless and playful way is to use a toy or object that makes a sudden noise or movement, such as a toy mouse that squeaks or a feather wand that moves quickly. This can startle your cat in a fun and safe way, providing entertainment for both you and your feline friend. Remember to always monitor your cat's reaction and ensure that they are not overly stressed or frightened.