The ornamental design for a mouse, as shown and described.
FIG. 1 is a perspective view thereof;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a right side elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a top plane view thereof; and,
FIG. 7 is a bottom plane view thereof.
The broken lines and the areas within in FIG. 3 are included for the purpose of illustrating boundary lines and unclaimed portions and form no part of the claimed design.