Ryan Reynolds kidnaps Fred Savage in 'Once Upon a Deadpool' trailer

Ryan Reynolds' Deadpool kidnaps former child star Fred Savage to appear in Once Upon a Deadpool, the family-friendly take on Deadpool 2.

Savage's inclusion in the film is described by 20th Century Fox as "an homage to Savage's starring role in the 1987 bedtime-story classic The Princess Bride.'" Savage is also known for playing Kevin Arnold on the '90s family drama The Wonder Years.

The first trailer, released on Monday in the US (Tuesday AEDT), shows a skeptical 42-year-old Savage bristling at the idea of being in the movie. When he insists he doesn't need Deadpool, Reynolds replies, "You need me to untie you once we're done."

Savage is unconvinced, asserting that he prefers Marvel movies. Reynolds reminds him that the Deadpool pics are Marvel movies and Savage counters, "But you're Marvel licensed by Fox. It's like if the Beatles were produced by Nickelback. It's music, but it sucks."

Reynolds replies, "You were nicer as a kid."

WATCH: 'Deadpool 2' official trailer (Post continues.)

Fox is billing the movie, which will run for 12 days from December 12 to 24 in the US, as "a fairy tale that gives zero Fs."

For every ticket sold, US$1 will go to the charity Fudge Cancer, also known as F--k Cancer.

"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 in a statement.