I had something like this as a kid, but it was a camel where you could fill it up through tye hump and pour it out of the mouth. I didn't really understand it, so i always filled it up with syrup and then water and it would "magically" separate it. I fully believed that this is what it's for... Until now. I wonder if that vamel is still around somewhere, this post gave me a massive nostalgia boost.