In addition to the 15 regular variants shown on this page, there is also a 16th variant cover shown, for which 25 different versions were made. This 16th variant is the "Retailer Heroic Exclusive" cover. The cover art is the same for all 25 versions of this cover - it shows 4 characters standing atop a sign. In each of the 25 "Retailer Heroic Exclusive" covers the text of the sign is different, showing the name of each of the 25 retailers.
Those 25 retailers for which a "Retailer Heroic Exclusive" cover was made are:
All About Books & Comics
Another Dimension Comics
Bazinga Comics
Beyond Comics
Cards, Comics & Collectibles
Collectors Corner
Comic Oasis
Discount Comic Book Service
Dr. No's Comics & Games Superstore
Fantasy Realm
Far Jack's Comicrypt
Forbidden Planet
Jetpack Comics
Keith's Komix
Larry's Comics
MaximuM comics
Midtown Comics
Mile High Comics Jason Street Mega Store
Newbury Comics
Rockin' Rooster
Silver Snail Comics
Stormwatch Comics
Things From Another World
Ultimate Comics
Westfield Comics