These little guys are dried out, leaving the top rigid and sharp, like armor. The bottom is all covered in unappetizing protrusions known as "tube feet."
So how does one eat a starfish? With sharp armor on one side and tube feet on the other, you don't want to eat the outsides. All the good stuff is safely tucked away inside this fella's legs. The easiest way to eat the starfish is first to break off one leg (with apologies to the starfish). Then, use your fingers to pry open the leg via the fissure in the middle of the tube feet. It should look roughly like this:
See that olive green mush inside the leg? There's your food. It's not particularly classy, but the thing to do now is hold that leg open and use your tongue to dig out that succulent starfish meat. If you've ever eaten river crabs in China, you'll find that the starfish tastes just like the brain area of the crab. It also tastes very similar to the sea urchins that you can find all over Qingdao.
Note that the sea urchin meat is hidden under a layer of egg custard for some reason.
If you've never had the pleasure of eating river crab or sea urchin, I guess the closest way I can approximate the taste is that starfish tastes the way a beach smells at low tide. The texture is soft, moist, and mushy. I'm probably not making it sound very appetizing. But that's how it is. It's no coincidence that sea urchin (which, again, tastes very similar) is considered an acquired taste. I'm going to guess that this is not going to be a favorite for everybody. For the seafood lovers out there, though, it's worth a try. It's a bit more expensive than a lot of street food (you will probably pay between 10 and 20 RMB for a single starfish, depending on how touristy of an area you're in). One other note: it's not clear how much the locals eat starfish on a day-to-day basis. Though it is traditionally eaten in the Qingdao area, these days it seems to be mostly for tourists. For travelers looking to have the "local experience," this might be off-putting. Which is too bad, because the starfish is a unique local treat. This might be one of those times where it's okay to jump on the touristy bandwagon and give it a go.