A cough produced by a smoking member of the human race usually convincing other smoking members that it _is_ a bad habit and you _will_ die from it sooner or later.
Marlboro Cowboy: Cough! Rwatsh! Murph.
You: OMG!
MC: Brwhafargh blur blorg!
Y: You really should quit man, it 'll kill ya!
MC: Ough, The Cough of Death becomes worse... Maybe tomorrow...
Usually a phenomenon present in the cannabis community amongst stoners and sufferers of conditions like acute bronchitis or pneumonia which refers to the excessive, continuous, almost always painful, heave inducing, tomato face consequent coughing fit the results in great exhaustion.
Guy: Dude I was at my buddy's last night and I took a huge hit from his 3 chamber honeycomb bong! Made me cough up a lung!