Trivia: Sweet Pete's tragic backstory is similar to Bobby Driscoll who voiced Peter Pan in the original Disney film. Many people have expressed disgust over this, as it distastefully satirizes Driscoll's own personal tragedy and downfall of being unable to find work after getting older.
Trivia: When Nancy Tremaine (Idina Menzel) is singing to Morgan about her memories to make the tree come to life again she sings a line "Let it glow, let it glow." This is an homage to Idina Menzel as Elsa in Frozen singing "Let it Go".
Trivia: Sergei from Secret Life of Pets 2 can be seen in the bank.
Trivia: During the end credits, you can see various drawings. One of the drawings is The Backson from Winnie the Pooh (2011), which was also directed by Don Hall.
Trivia: Spoiler! There is a mid-credits scene with Commander Burnside. He is complimenting his space shield that also zaps giant bugs.
Trivia: Smart Beavis and Smart Butt-Head are based on the Watchers from Marvel Comics.
Trivia: The film is inspired by the classic Mel Brooks comedy "Blazing Saddles," and is intended to be a child-friendly retelling, with many near-identical sequences. In fact, it was originally titled "Blazing Samurai," and it would have been about an African-American man becoming a samurai. It was eventually retitled, and the studio decided to rework the narrative by making it about a dog living in a world of cats, in order to make the anti-racism message more subtle and "universal."