Okay, so Hattie the cat doesn't literally know ALL the words! Still, she knows exactly when to chime in, which in our book makes her one melodious moggy. And clearly Hattie has every reason to be happy AND know it. We're guessing her adoring human slave gives her all the attention any pampered puss could desire. Be sure to turn up the volume--and watch to the end for the big finish!
WATCH THE VIDEO HERE: