The cat's name is Rocky. He is 2 years old and his owners are French (Daisy and Yann). Rocky used to stand up because he couldn't see the birds through the windows, and wanted to, so he stood up. Why does he raise his leg in the middle of the video? Probably because there was a bird outside, according to Daisy, or maybe a dog wandering around. Rocky hates dogs.Video after the jump.
He doesn't stand up too often any more because Daisy and Yann moved their stuff, so now Rocky can see everything without having to go bipedal.
He's also able to sit on his bottom like a human (this cat is crazy). Basically, that's it :-)