The ornamental design for a scooter, as shown and described.
FIG. 1 illustrates a front, top perspective view of a scooter;
FIG. 2 illustrates a back, top perspective view of a scooter;
FIG. 3 illustrates a front, bottom perspective view of a scooter;
FIG. 4 illustrates a front view of a scooter;
FIG. 5 illustrates a back view of a scooter;
FIG. 6 illustrates a right side view of a scooter;
FIG. 7 illustrates a left side view of a scooter;
FIG. 8 illustrates a top view of a scooter; and,
FIG. 9 illustrates a bottom view of a scooter.
The broken, dashed lines shown in the various figures are included for the purpose of illustrating environment and do not form any part of the claimed design.