Trivia

John Cena actually played the piano.

The piano scene was inspired by a moment when James Gunn received news that his dog was dying while working on the show. John Cena played him a song while he waited for his ride to the airport. "John got up and sat at the grand piano and played the most beautiful rendition of The Pixies' "Where Is My Mind." It crushed me and yet soothed me and everyone around me was crying. I wanted to capture some semblance of that moment with this song", Gunn recalled.

Peacemaker plays the piano version of Motley Crue's "Home Sweet Home". James Gunn suggested on Twitter that music serves as an outlet for Cristopher to express himself: "Chris Smith is an artist who has been decimated by this world. He's been decimated by who his parents are, what his surroundings are, and the entire culture he's been brought up in. This is not to say he is not culpable; he is. But he is emotionally mute, unable to express himself."

The rendition of "Home Sweet Home" that John Cena plays was arranged by John Murphy, who was a composer for The Suicide Squad (2021) and Guardians of the Galaxy Vol. 3 (2023).

There are various photos scrapbooked into the diary that Leota Adebayo planted in Peacemaker's home, including a drawing of a single eye covering a human's face and a close-up photo of an eye surrounded by blue. Both of these could be references to Starro, the giant one-eyed starfish-looking alien featured in The Suicide Squad (2021). Since Starro is easily the most well-known single-eyed DC villain and one Peacemaker already has a history with in the DCEU, it'd make some sense for his fake diary to include some references to Starro.