I claim the ornamental design for a pickle ball, as shown and described.
FIG. 1 is a front view of a pickle ball;
FIG. 2 is a first side view of the pickle ball of FIG. 1;
FIG. 3 is a rear view of the pickle ball of FIG. 1;
FIG. 4 is a second side view of the pickle ball of FIG. 1;
FIG. 5 is a top view of the pickle ball of FIG. 1; and,
FIG. 6 is a bottom view of the pickle ball of FIG. 1.
The ornamental design that is claimed is shown in solid lines in the drawings. The broken (dashed) lines shown in the figures are included for the purpose of illustrating portions of the pickle ball that form no part of the claimed design.