1.n an ordinary house fly that has metamorphosed into a devoluted super fly by consuming the excreted by-product from the skin of a tweaker (a life-form under the influence of methamphetamine). Tweaker flies become extremely aggresive, develop a nuclear-hardened exo-skeleton, their appendages grow to triple normal size. Avoid tweaker flies at all costs: Tweaker flies will dive-bomb you to get their next dose of methamphetimine (they do not care if you are spun ducky woo woo or not). Tweaker flies wings fold back like F-14 fighter jet swept wings. They have sex constantly (partners' gender is unimportant). Tweaker flies love cockroaches sexually most of all.
Dude, don't go to 12th Street; the tweaker flies have taken over Merced and are learning to speak English. One did a fly-by and told me "Give me you methamfriendofmine.