FIG. 1 is a front perspective view of a cigarette urn, according to the invention. FIG. 2 is a top view of the cigarette urn shown in FIG. 1. FIG. 3 is a right side view of the cigarette urn shown in FIG. 1, which is identical to the left side view; and, FIG. 4 is a bottom view of the cigarette urn shown in FIG. 1. The broken lines are shown for illustrative purposes only and form no part of the claimed design.