Because I'm not quite as creative as my brother-in-law, and in an effort to curb the chunkiness that Linus seems to be acquiring, I got him a mouse toy. Something to stalk, chase, and jump in the air to catch. Turns out I'm having just as much fun with it as he is. He gets so into it that he'll jump 3 to 4 feet in the air to catch it. I'm guessing it's probably coated in catnip. This picture was taken before he managed to rip the mouse off the string and I had to retie it to the tab.