The ornamental design for a sharksleepingbag, as shown and described.
FIG. 1 is a front view of a shark sleeping bag;
FIG. 2 is a rear view thereof;
FIG. 3 is a right side view thereof, the left side view being a mirror image thereof;
FIG. 4 is a top view thereof;
FIG. 5 is a bottom view thereof; and,
FIG. 6 is a perspective view thereof.
The horizontal dash-dash broken line shown in FIG. 4 illustrates a portion of the shark sleeping bag that forms no part of the claimed design. The remaining dot-dash broken lines shown in FIG. 4 illustrate the boundary of the claimed design and form no part thereof.