I claim the ornamental design for a cow figure, as shown and described.
FIG. 1 is a front elevation view of a cow figure, showing my new design, the broken line showing of the clothing is for illustrative purposes only, and forms no part of the claimed design;
FIG. 2 is a back elevational view thereof;
FIG. 3 is an enlarged bottom view thereof;
FIG. 4 is a right side elevational view thereof, the left side elevational view being a mirror image; and,