My girlfriend had a birthday sometime back, and I threw her a party with a Spongebob theme, because she likes the show (we're in our twenties). One of the decorations was a helium-filled mylar Spongebob balloon. Well, our cat was nervous by it from the start. When he would see it, he would freeze and stare at it until he felt comfortable. A few months passed and the balloon was still floating, by this time a few inches off the ground. Last night, I got up to go to the kitchen and I see our cat run out of the bedroom and back up against the wall. A few seconds later I see the Spongbob balloon slowly float out of the bedroom, turn, and then slowly float towards our cat. Our cat shrunk in horror as the balloon ever so slowly floated towards him. After calling my girlfriend over and us laughing, I "saved" our cat and moved Spongebob away. The funny thing is that our cat has attempted attacks on animals much bigger than himself (friends' dogs), but he has a fear of inanimate objects such as the balloon and a stuffed animal.