dewfiend
A dewfiend is someone hopelessly addicted to Mountain Dew. These people are easily recognizable by their often unkempt hair and sloppy clothes, dark circles under their eyes, and the ever handy can of Dew in their sweaty hands.
"Dude, Jim is such a dewfiend. He drank three liters of the stuff yesterday!"
"I sure feel sorry for his future kids..."
"I sure feel sorry for his future kids..."