The Denver Broncos had many years of great battles with future Hall of Fame quarterback Tom Brady, one of the best professional athletes of all time. In fact, the Broncos had Brady's number while he was a member of the New England Patriots, at least up until the Broncos were the laughing stock of the league from 2017-19.
Brady has a career record of 9-9 against the Broncos (including the playoffs and including his time with the Buccaneers), but he's not done trying to beat them just because he's done playing. He's part owner of the Las Vegas Raiders, which is already enough reason to hate him more if you're a Broncos fan.