FIG. 1 is a top perspective view of a tub drain cover showing my new design;
FIG. 2 is a bottom perspective view thereof;
FIG. 3 is a front elevational view thereof, the rear elevational view, the left elevational view, and the right elevational view being identical thereto;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof; and,
FIG. 6 is a cross-sectional view taken along line 6-6 in FIG. 4.
The broken lines showing the spherical knob in FIGS. 1-4, and FIG. 6 is included for the purpose of showing environmental structure and forms no part of the claimed design.