The ornamental design for a hammock, as shown and described.
FIG. 1 is a perspective view of a hammock showing our new design;
FIG. 2 is an enlarged view of the claimed subject matter of FIG. 1 shown in isolation from the environment for clarity thereof;
FIG. 3 is a top view thereof;
FIG. 4 is a perspective view of the hammock of FIG. 1 shown in a broken line environment of a stand thereof;
FIG. 5 is an enlarged view of the claimed subject matter of FIG. 3 shown in isolation from the environment for clarity;
FIG. 6 is a perspective view of an alternative embodiment of a hammock showing our new design;
FIG. 7 is an enlarged view of the claimed subject matter of FIG. 6 shown in isolation from the environment for clarity thereof;
FIG. 8 is a top view thereof;
FIG. 9 is a perspective view of the hammock of FIG. 6 shown in a broken line environment of a stand; and,
FIG. 10 is an enlarged view of the claimed subject matter of FIG. 8 shown in isolation from the environment for clarity.
The broken lines immediately adjacent the shaded areas represent a boundary of the claimed design. The remaining broken lines illustrate portions of the hammock, and a hammock stand, which is the environment of the hammock. None of the broken lines form part of the claimed design.