FIG. 1 is a front elevational view of motorcycle tail light showing our new design; FIG. 2 is a rear elevational view thereof; FIG. 3 is a bottom plan view thereof; FIG. 4 is a top plan view therof; FIG. 5 is a right side elevational view thereof; FIG. 6 is a left side elevational view thereof; and, FIG. 7 is a perspective view thereof.