In 'Dear Santa,' Jack Black portrays Satan who appears to fulfill the wishes of Liam, played by Robert Timothy Smith, after a spelling mistake directs the boy's letter to him instead of Santa Claus. The film also stars Keegan-Michael Key, Brianne Howey, and Hayes MacArthur, with a notable cameo by Post Malone. The narrative weaves through various comedic and bizarre scenarios, including revenge on a disagreeable teacher and an unlikely visit to a Post Malone concert, showcasing Black's well-known comedic flair.

While 'Dear Santa' attempts to capture a unique angle on holiday movies, critics have pointed out its uncertain tone and questionable appeal to its intended demographic. The film has been described as a mix between a children's movie and a typical Farrelly brothers' adult comedy, leaving some viewers confused about its target audience. Despite the criticisms, Jack Black's performance has been highlighted as a redeeming feature, bringing energy and humor to the film.

The Farrelly brothers shared insights into the decade-long development of 'Dear Santa,' emphasizing the challenges of balancing comedy with a family-friendly Christmas story. They also hinted at potential future projects, including a possible return to the 'Dumb and Dumber' series. The directors expressed their interest in exploring different genres, possibly even a horror film, showcasing their willingness to diversify their cinematic portfolio.