The ornamental design for a petlitterscoop, as shown and described.
FIG. 1 is a perspective view of a pet litter scoop showing my new design;
FIG. 2 is a top plan view thereof;
FIG. 3 is a bottom plan view thereof;
FIG. 4 is a front elevational view thereof, the rear being a mirror image thereof;
FIG. 5 is a right-side elevational view thereof;
FIG. 6 is a left-side elevational view thereof; and,
FIG. 7 is a perspective view of the pet litter scoop according to a second embodiment, the only difference being the number of tines, it being understood that all other areas are substantially the same as those of the first embodiment.