We report the serendipitous discovery of a new, very low luminosity, cool degenerate in the region of Taurus. The object was found as a very high proper-motion star ( mu = 1."3 yr-1) on seven I-band UK Schmidt Telescope plates, dating from 1987 to 1994, via digitized scans from the new, fast, high-precision microdensitometer SuperCOSMOS. Photometry and spectrophotometry indicate that the object has a temperature comparable to those of the handful of coolest white dwarfs currently known ( T~3900 K). We discuss the relevance of this discovery to current research concerning Galactic structure and evolution.