By performing the Mannequin Challenge, of course.
"I probably looked like an idiot, but that's part of having fun," Flacco said with a smile. "Hopefully, some people can make fun of me and do all that."
Flacco came up with the idea of adding his take on the social media video trend while running out onto the field Thursday night. Someone told running back Terrance West to do the Mannequin Challenge as he was coming out of the tunnel, which led Flacco to think about freezing while spiking the football if he scored a touchdown.
Because he threw a touchdown pass instead of scoring one, Flacco decided to stand still with his fist pump, which didn't get the reaction that he was seeking.
"I went running over to the sideline and asked a bunch of people," Flacco said. "Some people saw it, and some people didn't."
Coach John Harbaugh was among those who missed Flacco's celebration.
"Maybe that's a good thing, based on the way he described it," Harbaugh said.
The Ravens' kickoff team did the Mannequin Challenge after a touchback during the game, and the entire team stood still in the locker room after a victory that put them in sole possession of first place in the AFC North.
Flacco wasn't finished, either. After his two-point conversion with Kyle Juszczyk, he went up to high-five the fullback and they froze with their hands in the air.
"The refs kind of warned me, 'Hey, that might have been close to a planned tag-team celebration,'" Flacco said. "But when you're out there and you're winning football games, it's a lot of fun."