We claim the ornamental design for a foam bell hat, as shown and described:
FIG. 1 is a perspective front view of an embodiment of a foam bell hat according to the present invention.
FIG. 2 is a front elevation view of the foam bell hat of FIG. 1. The rear elevation view of the foam bell hat is identical to the front elevation view thereof.
FIG. 3 is a left side elevation view of the foam bell hat of FIG. 1. The right side elevation view of the foam bell hat is identical to the left side elevation view thereof.
FIG. 4 is a top plan view of the foam bell hat of FIG. 1; and,
FIG. 5 is a bottom plan view of the foam bell hat of FIG. 1.
The portions shown in broken line are not claimed.