The type of person in the NFL that hardly anyone speaks off anymore because he never won a title. However, Moon was a competitive individual who gave it his all.
He mainly played for the Houston Oilers for ten years. The Oilers fell part in the mid 90's and Moon went over to the Minnesota Vikings. The Vikings franchise during this time was also undergoing remodeling. Everybody remembers Chris Carters and Randy Moss but nobody ever mentions Moon anymore.
Moon tried his best but for many reasons couldn't win a title. He paid his dues in the CFL much like other players (like Steve Young who didn't go directly to the NFL). This I feel should be pointed because a lot of athletes go directly from college or high school to the pro sports and they haven't paid their dues.
Much like other ringless NFL quarterbacks (Jim Kelly) has shown in his interviews and his competitive play to be a respectable performer for the NFL.