So what did I missed? Period.
Oh, so anyway, I think I know from where that Hydralisk came... He came from sky, which is a prove Azeroth is not flat and not made from Cheese! Also, looks like my astro-peasants which are responible for Apeollo are able of detecting from where hydralisks came, but it will take some time to find out how to use these Made by Goblins telescopes...