The ornamental design for a funnel, as shown and described.
FIG. 1 is a front view of a funnel showing my new design;
FIG. 2 is a rear view thereof;
FIG. 3 is a left side view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a top plan view thereof;
FIG. 6 is a bottom plan view thereof;
FIG. 7 is a perspective view thereof;
FIG. 8 is a top front perspective view thereof, shown in a first position of use attached to an unclaimed grill drawn in broken lines; and,
FIG. 9 is a bottom front perspective view thereof, shown in a second position of use attached to an unclaimed grill drawn in broken lines.
The broken lines in FIGS. 8 and 9 showing a grill depict environment and form no part of the claimed design. All other broken lines depict portions of the funnel that form no part of the claimed design.