Tragic day for the Cleveland Browns ... the team's first-ever live mascot, Swagger, has passed away after a battle with cancer. He was 6 years old.
The 145-pound bullmastiff joined the Browns as a puppy at the beginning of the 2014 season ... and ran out with the players before every home game until Week 10 of the 2019 season.
The only home game Swagger missed was in 2017 ... when the Browns played in London.
Swagger's son, SJ, took over the mascot duties as the cancer progressed ... and the beloved dog served as "Dawg Pound Captain" during his final Browns game.