The ornamental design for a multifunctionalbackpack, as shown and described.
FIG. 1 is a front, right side, and top perspective view of a multifunctional 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;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is a front, right side, and top perspective view shown in a manner of use with a tripod shown in broken lines.
The broken lines shown in FIG. 8 illustrating the tripod form no part of the claimed design. The broken lines shown in FIGS. 1-8 on the multifunctional backpack illustrate stitching that is part of the claimed design.