Intimidation

Storm is easily startled. An unfamiliar or sudden noise will do it usually, or me brushing my teeth. Now, he is not a very large cat, so it's understandable he tries to make himself appear as big as possible, by turning sideways and expanding his tail and such. But then he does the silly hopping thing, and doesn't look big and scary at all anymore. In fact he makes me laugh out loud when he does that.

Or perhaps that is the idea, when your 'enemy' is on the floor laughing, they are not likely to attack you. Hmmm.....