We claim the ornamental design for a head covering, as shown and described.
FIG. 1 is a perspective view of the head covering design of the present invention,
FIG. 2 is a front elevation view of the head covering design of the present invention.
FIG. 3 is a rear elevation view of the head covering design of the present invention.
FIG. 4 is a top plan view of the head covering design of the present invention.
FIG. 5 is a bottom plan view of the head covering design of the present invention.
FIG. 6 is a side elevation view of tile head covering design of the present invention; and,
FIG. 7 is the opposite side elevation view of the head covering design of the present invention, as shown in FIG. 6.
The broken lines in FIG. 1 showing the wearer of the head covering of the present invention are included for the purpose of illustrating use and environment and form no part of the claimed design.