Fry Guy's post in SOW Mini was marked as the answer
If anyone's still looking for the black "Son of Worm" mini helmet, I found a few of them for sale on eBay. There were still four available at the time of this posting. If eBay's not your thing, then be sure to check with the stadium team store by the end of Spring Football Practice. Vanessa recently let me know that they are planning to receive another shipment just in time for the Green and White Game on April 18th.