Beheeyem -- based on actual reported aliens (well, mostly). Given how Beheeyem is a broad pastiche of the alien conspiracy genre it seems only natural they'd have a world-wide invasion going on.
I suppose realistically the original Beheeyem would be named after Nimbasa City, since these things usually take the name of the closest town when they happen outside of one... assuming the 'Dex entries actually meant Unova's desert and not the game's unseen equivalent of Roswell.
