"The only F word in this movie is Fred Aaron Savage. #OnceUponADeadpool #AsYouWish," Reynolds captioned the image, in reference to the film's PG-13 rating, a first for the usually R-rated Deadpool series.
The poster is Christmas-themed and features the titular hero sitting behind a smiling Savage on the reindeer wearing a Santa Claus hat.
Once Upon a Deadpool, which will be available in theaters from Dec. 12 to Dec. 24, is an edited, PG-13 version of Deadpool 2 that features new scenes with Savage.
The scenes with Savage pay homage to the actor's role in 1987's The Princess Bride where the actor, as a young boy, was told a bedtime story. Reynolds will be kidnapping Savage in Once Upon a Deadpool in order to place him in a similar, bedtime story situation.
For every ticket sold for the film, $1 will be donated to the temporarily renamed Fudge Cancer charity.
"Fox has been asking for a PG-13 basically since the start in 2006," Reynolds said recently while speaking with Deadline. "I've said no since 2006. Now, this one time, I said 'Yes' on two conditions. First, a portion of the proceeds had to go to charity. Second, I wanted to kidnap Fred Savage. The second condition took some explaining..."
"While my participation in this film was anything but voluntary. I am happy to learn that Fudge Cancer will be the beneficiary of this shameless cash grab," Savage said.