Flusher first appears in the episode A Mine is a Terrible Thing to Waste Part I and Part II. He answers Sludge's ad for "A heinous henchman to serve a Machiavellian master". He says he's the man for the job even though he doesn't know what the ad means.
He is tall and muscular, with a deep voice. He has blonde hair and has a gold front tooth. Flusher is obviously stupid, which suits Sludge fine, as Flusher obeys orders easily.