The ornamental design of a bottlecap accessory, as shown and described.
FIG. 1 is a first perspective view of a bottle cap accessory in accordance with the present invention;
FIG. 2 is a second perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a back view thereof;
FIG. 5 is a top view thereof;
FIG. 6 is a bottom view thereof; and,
FIG. 7 is a left side view thereof, the right side view being a mirror image.
The broken lines showing the football icon and element on the bottom edge of the accessory in the FIGs. illustrate portions of the bottle cap accessory that form no part of the claimed design.