A person in a marching band, whether it be Highschool or College, who constantly causes a disfigured shape or form within the structure/picture the band is trying to display. This person has either very poor perception, disabled in some way, or just lazy.
Guy 1: "Dude, the flower in our last formation looked like a giant dick on field..."
Guy 2: "It was that dumb clarinet bitch..."
Guy 1: *Facepalm* *sigh* "Band cancer, right there...."