FIG. 1 is a front elevational view of a building block showing my design;

FIG. 2 is a left side view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a bottom plane view thereof;

FIG. 5 is a top plane view thereof;

FIG. 6 is a rear elevational view thereof;

FIG. 7 is a perspective view thereof;

FIG. 8 is another perspective view thereof;

FIG. 9 is a front elevational view of a modified embodiment of the design shown in FIGS. 1-8, showing four-piece block formed from four serially connected building blocks showing my design, wherein each side of the four-piece block has the same pattern;

FIG. 10 is a left side view of the four-piece block of FIG. 9;

FIG. 11 is a rear elevation of the four-piece block of FIG. 9;

FIG. 12 is a right side view of the four-piece block of FIG. 9; and,

FIG. 13 is an elevational view of a second modified embodiment of the design shown in FIGS. 1-8, showing four-piece block formed from four serially connected building blocks showing my design, wherein each side of the four-piece block has four different patterns.