The ornamental design for a zipperpull, as shown and described.
FIG. 1 is an isometric view of a zipper pull showing my new design from one viewpoint.
FIG. 2 is an isometric view thereof from another viewpoint.
FIG. 3 is a front elevational view thereof.
FIG. 4 is a rear elevational view thereof.
FIG. 5 is a right side elevational view thereof.
FIG. 6 is a left side elevational view thereof.
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
Stippling and contour lines shown in the drawings are intended to represent the approximate three-dimensional contours of the design, and are not intended to indicate surface decoration. The broken lines illustrating the top board of the slider form no part of the claimed design.