The ornamental design for a suit for an animal, as shown and described.
FIG. 1 is an elevated front perspective view of a suit for an animal showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof; and,
FIG. 4 is a side elevational view thereof, drawn to a reduced scale with respect to FIGS. 1 through 3.
The structural features in FIGS. 1 through 4 and the horizontal fastening elements in FIGS. 1 and 2 have been shown in broken lines for the purpose of illustrating portions of the suit for an animal that form no part of the claimed design.