Snapback hats are very collectible, although typically by sports fans. In 1997, Harvey had a snapback made with embroidered patches of some of their characters. The company that made the hats, Colosseum Athletics, Inc., is still in business, but does not seem to make hats any longer.

The seller had two of these for sale, I wish I had bought both. I would have cut the tag off one and worn it to comic conventions!

Harvey Snapback Hat in turquoise