The ornamental design for a pettoilet, as shown and described.
FIG. 1 is a front perspective view of a pet toilet showing my new design;
FIG. 2 is a rear perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof; and,
FIG. 7 is a top plan view thereof.
The broken lines shown depict environmental subject matter, are included for the purpose of illustrating the unclaimed portions of the pet toilet and form no part of the claimed design. The line-dot-line broken lines indicate boundary lines between the claimed portions and the disclaimed portions, are for illustration only and from no part of the claimed design.