FIG. 1 is a top perspective view of a wall block according to one embodiment of the design;

FIG. 2 is a bottom perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a right side elevational view, the left side being a mirror image thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof;

FIG. 8 is a top perspective view of a wall block according to a second embodiment of the design;

FIG. 9 is a bottom perspective view thereof;

FIG. 10 is a front elevational view thereof;

FIG. 11 is a rear elevational view thereof;

FIG. 12 is a right side elevational view, the left side being a mirror image thereof;

FIG. 13 is a top plan view thereof;

FIG. 14 is a bottom plan view thereof;

FIG. 15 is a top perspective view of a wall block according to a third embodiment of the design;

FIG. 16 is a bottom perspective view thereof;

FIG. 17 is a front elevational view thereof;

FIG. 18 is a rear elevational view thereof;

FIG. 19 is a right side elevational view, the left side being a mirror image thereof;

FIG. 20 is a top plan view thereof;

FIG. 21 is a bottom plan view thereof;

FIG. 22 is a top perspective view of a wall block according to a fourth embodiment of the design;

FIG. 23 is a bottom perspective view thereof;

FIG. 24 is a front elevational view thereof;

FIG. 25 is a rear elevational view thereof;

FIG. 26 is a right side elevational view, the left side being a mirror image thereof;

FIG. 27 is a top plan view thereof; and,

FIG. 28 is a bottom plan view thereof.