I claim the ornamental design for a mobility accessory, as shown and described.
FIG. 1 is a front perspective view of my new and original design for a mobility accessory thereof;
FIG. 2 is a back elevated view thereof;
FIG. 3 is a right side elevated view wherein the left side is a mirror image thereof;
FIG. 4 is a top plan view of thereof;
FIG. 5 is a bottom plan view thereof; and,
FIG. 6 is a left side elevated view showing the mobility accessory in a position of use.
The broken line in FIGS. 1 through 6 are included to illustrate portions of the mobility accessory and form no part of the claimed design. The canopy and the mobility scooter shown in broken line in FIG. 6 are included for the purpose of illustrating the mobility accessory in a position of use and form no part of the claimed design.