Hang on, don't go just yet, it's actually far nicer than it sounds!
This is something I was introduced to last time I was in Berlin. Apparently it's quite popular in Germany. I've never seen anything like it in this country, and so after spending Saturday night in a German beerhall in London (complete with oompah band) I felt like trying to make some of my own. So, here's how I did so, if you want to try: you can probably find better recipes elsewhere, from people who know what they're doing, but this one turned out to taste pretty good.
First what you need is a German wheat beer (Weißbier). If you haven't tried one before then you should certainly try a couple unadulterated first. It's very different from what we think of as lager. You should be able to find one fairly easily.
More difficult to come by is the other ingredient: banana juice. I've no idea how you actually juice a banana, but if you do then let me know. I tried to buy some at the supermarket, and despite the dozens of obscure berry juices on offer was unable to find any pure banana juice. However, I was able to find something on the Polish aisle that was at least mostly banana juice, which I reasoned was better than nothing.
That's the hard part. When you've got the ingredients, simply fill a glass 3/4 full with Weißbier and then top up with banana juice.
Don't let the colour put you off. Just give it a try and enjoy!
And if you do enjoy it, maybe you might be interested in my books?