Yes he did. He beat every team (including his own 49ers) that existed during the time he played. There are teams that didn't exist yet that he didn't beat, but he definitely deserves the statistic first to beat all teams (rather than Brett Farve). The info can be found on this page.
http://www.pro-football-reference.com/players/M/MontJo01/gamelog/#stats_playoffs
Brett Favre has beaten every team in the nfl.
They were the 6th ranked team in the nation before Brett Favre and the Southern Miss Golden Eagles beat them.
The Bengals
He is the only quarterback in the NFL to have beat every team, including the Cowboys. Yes, he has beaten them.
no
The only player I know of is Brett Favre.
New England Patriots
Brett Favre was drafted by and debuted with the Atlanta Falcons.
Terrel Owens and Brett Favre
Brett Favre retired from the National Football League after the 2010 season.
31, the only team that Brett Favre has not lost to is the Kansas City Chiefs.
Eagles