Nipple

FIG. 1 is a perspective view of a nipple, illustrating my new design;

FIG. 2 is a front elevational view;

FIG. 3 is a rear elevational view;

FIG. 4 is a right-side elevational view;

FIG. 5 is a left-side elevational view;

FIG. 6 is a top plan view; and,

FIG. 7 is a bottom plan view.

In FIGS. 6 - 7 , the unshaded areas enclosed by broken lines form no part of the claimed design, while broken lines within those areas indicate environmental structure that also forms no part of the claimed design.