The ornamental design for an aerobic headcover, as shown and described.
FIG. 1 is a front elevation view of an aerobic head cover;
FIG. 2 is a rear elevation view thereof;
FIG. 3 is a right side elevation view thereof;
FIG. 4 is a left side elevation view thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a rear perspective view thereof.
The dash-dot-dash broken lines define portions of the aerobic head cover that form no part of the claimed design. Any broken lines within the bounds of the dash-dot-dash broken lines do not form part of the claimed design. The even length broken lines along the surfaces of the aerobic head cover depict features that are not claimed.