The ornamental design for a pettunnel, as shown and described.
FIG. 1 is a top and front perspective view of a pet tunnel showing our new design;
FIG. 2 is a top view thereof, the bottom view is identical to the top view shown;
FIG. 3 is a left-side view thereof, the right-side view is identical to the left-side view shown;
FIG. 4 is another top and front perspective view thereof shown partially collapsed;
FIG. 5 is another top and front perspective view thereof shown fully collapsed;
FIG. 6 is a front view of FIG. 5;
FIG. 7 is a top view of FIG. 5, the bottom view is identical to the top view shown; and,
FIG. 8 is a left-side view of FIG. 5, the right-side view is identical to the left-side view shown.
The broken line showing of the cat in FIGS. 1 and 4 depicts environment; the remaining broken lines depict portions of the pet tunnel. The broken lines form no part of the claimed design.