An animal (cat/dog/etc) missing a significant portion of an upper canine tooth. A Unifang is identified by an awkward smile with a single fang protruding from beneath the upper lip region. If a Unifang bites you, the bite mark can be recognized by the unsymmetric pattern of the missing canine portion.
Odie: Did you leave that bite mark on Jon's hand when you got busted stealing the lasagna?
Garfield: Let me guess, you noticed it has my Unifang trademark?
Much like the dreaded Unibrow, the Unibang (or Unibangs) are a continuation of a persons Unibrow connecting the hair line near the temples. It creates one continuous hair/eye brow.
"It took me all morning tweezing and plucking my Unibangs so that I didn't have one long continuous Unibrow."
The stereo-typical Asian chick haircut that is basically full bangs stopping at the ears and the rest of their hair falling straight down to end somewhere between the shoulder blades.