h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I've heard that this stufff is just Carlsberg renamed to sound greek.

Could be wrong though. It's still nice in the hot greek sun

Could be!

Mythos is a Greek beer but it isn't very nice. Most Greeks I knew when I lived there preferred Amstel.

Mythos is much nicer than Amstel! It's not up to the standard of Czech lager, though.

Well, it's not Carlsberg, as it is brewed by the Athenian Breweries (a company also responsible for the Greek versions of Amstel and Heineken). As a matter of fact, it is one of the few genuinely Greek labels - the others are Alfa and Vergina, although they are not particularly popular and few stores seem to stock them. In terms of the taste of Mythos, it is comparatively mild, perhaps a wee bit too mild, with a 5% content in alcohol. For some reason, it seems to be a favourite of German tourists. Recently, the Athenian Breweries released a Mythos Red ale, which strives to be reminiscent of McFarland and fails miserably. My recommendation (being Greek and a beer-drinker): Look for beer produced by microbreweries. Any Peiraiki (lager and red ale if I am not mistaken) is really good, as are the Craft Microbrewery ales.
Cheers!