I claim the ornamental design for a trouser accessory, as shown and described.
FIG. 1 is a rear perspective view of a back pocket of a trouser accessory showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a side view thereof;
FIG. 5 is a top view thereof;
FIG. 6 is a bottom view thereof; and,
FIG. 7 is an enlarged view of the back pocket shown in FIG. 3.
The dash-dot lines in the drawings represent a trouser and are included for illustrating environmental structure for the back pocket trouser accessory and form no part of the claimed design.
The even dashes shown on the back pocket of a trouser accessory represent stitches.