Picnic Backpack

FIG. 1 is a perspective view of a picnic backpack, showing the new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a right side elevation view thereof; and,

FIG. 6 is a top plan view thereof.

The broken lines depict portions of the picnic backpack that form no part of the claimed design. All surfaces not shown form no part of the claimed design.