The ornamental design for a tooth-shaped sand timer, as shown and described.
FIG. 1 is a perspective view of a tooth-shaped sand timer showing my new
design.
FIG. 2 is a front elevational view thereof on a reduced scale, the rear
view being substantially similar thereto but with the `face` omitted and
the base being flat;
FIG. 3 is a right-side elevational view thereof on a reduced scale, the
left side being a mirror image thereto.