Kubus is a popular Polish brand of thick natural juice (perhaps, more of a smoothie?) drink made of carrots and fruit. It is rich in vitamin C and comparatively speaking, probably, a most healthy drink. Children (and adults) in Poland love the stuff!
If you haven’t tried any before we’d recommend you get some soon. It’s also available at most Polish stores pretty much anywhere in Europe. We even discovered Kubus for sale at a Tesco supermarket the last time we were in England.