The ornamental design for a petbowl, as shown and described.
FIG. 1 is a front elevational view of a pet bowl showing my new design, the rear elevational view being a mirror image;
FIG. 2 is a left side elevational view thereof;
FIG. 3 is a right side elevational view thereof;
FIG. 4 is a top plan view thereof; and,
FIG. 5 is a bottom plan view thereof.
The portions in broken line form no part of the claimed design. The boundary of the broken line area on the bottom plate of the pet bowl extends up to the underside of the rim. The broken line portions seen within the sack in FIG. 4 corresponds to the lowest portion of the inner sack.