* AllStarCast
* BillingDisplacement: Trailer only. The film's opening credits are actually appropriate, starting with the three characters from the book in order of importance (Danny [=DeVito=] as the Lorax, Ed Helms as Once-Ler, and Zac Efron as Ted) and the rest following. [[NeverTrustATrailer The trailer on the other hand]] plays up Zac Efron and Taylor Swift, Ed Helms, and gives Danny [=DeVito=] an "AndStarring",
* HeyItsThatVoice:
** [[Film/HighSchoolMusical Troy Bolton]], hoping to fulfill his crush Music/TaylorSwift's dream of seeing a real tree, goes to see [[Film/TheHangover Stu]] who got into a fight with [[Disney/{{Hercules}} Philoctetes]] over said trees.
** [[Series/ModernFamily Gil Thorpe]] is Aloysius O'Hare the mayor who sells bottled air.
** [[Film/GroundhogDay Ned Ryerson]] is the Onceler's Uncle!
** In the Japanese version, Creator/MamoruMiyano and Creator/KoichiYamadera are Ted and O'Hare respectively. The Lorax is voiced by the Japanese comedian Ken Shimura.
*** So Miyano got to voice Zac Efron's role after Zac failed to get [[Manga/DeathNote one of Miyano's biggest roles?]] [[note]] Though rumor has it that Zac turned down the part saying something along the lines of "cast Asian actors for Asian characters," avoiding a RaceLift.[[/note]]
** In the 1972 special, Bob Holt ([[WesternAnimation/ChallengeOfTheGoBots Cop-Tur]], [[WesternAnimation/TheGreatGrapeApe Grape Ape]], [[WesternAnimation/{{Wizards}} Avatar]]) was [[ActingForTwo both]] [[TalkingToHimself The Lorax and Once-ler]].
* IronyAsSheIsCast: Despite Ted and Audrey being voiced by the star of the ''High School Musical'' movies and Taylor Swift respectively, their characters never sing a note.
* WordOfGod: On the DVD commentary, it is mentioned that after How Bad Can I Be?, 5 years have passed.

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