A lot of people call this "kill" but when I say "Git It, Onyx!" she does that. She grabs the ball, and shakes it, like she's killing it! It's SO cute! I just went with it when she started doing that. The easiest way to do that though is to get them all wound up, and excited, and then start shaking something, let them take it, and when they start shaking it, say "Git It!" or "Kill!" then praise them when they do this. And repeat! Sounds simple, right? LOL Good luck!