FIG. 1 is a perspective view of the new design for a showerhead;

FIG. 2 is a left elevational view of the new design for a showerhead, the right elevational view being a mirror image;

FIG. 3 is a top plan view of the new design for a showerhead, the bottom plan view being a mirror image;

FIG. 4 is a front elevational view of the new design for a showerhead; and,

FIG. 5 is a rear elevational view of the new design for a showerhead.

The broken lines in the Figures are for illustrative purposes only and form no part of the claimed design.