The words „ krummbuckliger hustensaftschmuggler“ refers to a person that has a very hinged over posture and is so stupid that they smuggle Cough Syrup. So basically a very ugly, and stupid person. This word would most likely be used in German or in the German-English mixture many people call „Denglish“. This word could also just be a small kind of mean nickname for your friends, since it’s not really harsh.