I've never heard of them being referred to as the Crown Beasts before...
And to the people muttering about being seen in public at what is unabashedly a kid's event, remember that this isn't ten years ago, where you'd have to wait in line while a store employee traded everyone a Mew, one at a time. These are wireless events, kids: you can stand outside the store and fire up your DS if you're worried about being seen. The fact that most GameStops are in malls or shopping centers facilitates this greatly, that you can stand just around the corner and do what needs doing. In the interest of full disclosure, that's exactly what I intend to do.
Same here. In my case, Gamestop is it's own store in the next city south from mine (well, technically it's two cities, but the drive is only fifteen minutes from my house), so all I have to do is find a parking spot directly in front of the store (any farther and the signal won't reach. Finding a spot should be easy unless the Starbucks next door to the Gamestop is heavily populated at the time). I can just park, download the event in each of my games, and be on my merry way.
For those who are still afraid of looking
too obvious... I dunno. Bring a shopping bag (or simply buy things beforehand) and put your DS into the bag, turned on and ready to download the event. Stop outside of the store and kneel down to "check" something inside of your bag. With your DS inside of your bag, connect to the store's wi-fi. Download the event, pause to rummage through the bag, wait until it's done downloading, and then leave. Further on, you can shut off your DS or whatever you need to do.
Or, if there are a bunch of kids about your age with their DS's out, just kind of lean on a wall near them and act natural. Being incognito isn't difficult.