This Cat Is Having a Great Dream

Or is he having a nightmare about being chased by a dog? We'll go with the happier interpreation: the cat in this video is having a dream of some kind, and we'll say he's dreaming of catching a mouse. Whatever, it must be quite a dream because kitty's legs are jerking, his tail twitches, his claws come out a some points, he makes yowling noises ... it's quite a performance.