- It is customary to hold on the last syllable at the end of a song. At the end of the "Thneedville" song, what word do they wind up on? The town's name, causing the chorus to make a raspberry in unison!
- "You wouldn't hit a woman!" *beat* " Dat's a woman?!"
- It's particularly funny since the Lorax's remark isn't sarcastic; he's 100% sincere in his surprise.
- Even better. When he bumps into her again much later, he nonchalantly refers to the woman as "sir".
- The Lorax's initial appearance being derailed when he's offered a marshmallow.
The Lorax: (offended) Gimme that!The Lorax: (beat)The Lorax: ... I'm going to eat this, but I'm highly offended by it!
- The Lorax saying to Past!Once-ler "You have been warned!"...and then having trouble reaching the door handle. Past!Once-ler proceeds to open the door for him with a deadpan expression on his face.
- When Present!Once-ler first begins his story:
Once-ler: It all started a long time ago...Ted: Can we start not so long ago, maybe?Once-ler: Do you want a tree?Ted: Yes, yes...Once-ler: Then it all started a long... LONG time ago!
- From one of the many preview clips, the Onceler asks why Ted is asking about trees instead of, "Break Dancing, wearing Bell-bottoms, or Playing the Donkey Kongs."
Once-ler: Why are you so interested in trees anyway? It's a girl, isn't it?Ted: What?! No!Once-ler: Really? 'Cause when a guy does something stupid once, well, that's because he's a guy, but if he does the same stupid thing twice, that's usually to impress some girl.Ted: Hey, she is not some girl! She's a woman! In high school. And she loves trees. And I'm gonna get her one.Once-ler: Aww. How nice to see someone so undeterred by things like... reality.Ted: Thank you.
- Some Fridge Brilliance: The Once-ler also did something stupid (cutting down the trees) for the second time to impress a girl: his mother.
- During the Onceler's Villain Song, cameramen take a picture of the Lorax, who later appears on an advertisement billboard for Thneed saying "Lorax Approved".
- The entirety of the Cut Song The Once-ler's Traveling Madness.
- "You and I will have separate grandchildren, and we will say to them..."
- "And then some other little critter's gonna come and make furniture out of our bones. And sit on it and have lovely dinners."
- Although a bit of a tearjerker as well, when the animals are building a circle around the cut down tree, at one point the largest barb-a-loot is holding a tiny little stone, while a humming fish is rolling along a stone bigger than it and clearly expresses his preference that they switch!
- The river scene and the dialogue between young!Once-ler and the Lorax after that scene.
Once-ler: I was heading into the light and you pulled me right back, and here I am! (hugs Lorax) You saved my life!Lorax: Yeah, well, you know, not that big a deal.Once-ler: It is a big deal! Look, I almost went over that waterfall! (realizes something) Wait...On my bed. How did my bed get in the river?Lorax: Uh, about that, uh...actually, um...Iputyourbedinthewater. (Once-ler drops him)
- "OK, I've got a big day tomorrow, and I'm gonna get some sleep..." (walks off screen. Beat, then walks back on screen slumped over) "...Right after I find my bed."
- "Oh, yes, right after the musical number about the kid who kept interrupting the story and was never heard from again."
- The air-delivery guy. He's a big guy with a high voice and gets a featured solo in both the opening and closing song. And he ONLY sings!
- O'Hare joins in the final musical number, seemingly about to change his ways....then says "Naaaah!" and starts singing "Let it die, let it die!" A Flat Character he may be, but at least a good joke can be made of that fact.
- The Once-ler trying to sell his first Thneed. It gets to the point that the price of the tomatoes being thrown at him is as much as he's charging for the Thneed.
- The Uncomfortable Elevator Moment during the big chase.
- Ted's unwavering smile makes it even better.
- When Ted's grandma tells him about the Once-ler. The fact that she can appear anywhere is funny itself.
- This line from the Cut Song, "Nobody needs a Thneed":
"The thneed is dumb./ The thneed is lame./ Who's the idiot who came up with that name?!/ *beat* /Alright, it was me."
- "Nice mustache."
- The opening Illumination Entertainment Vanity Plate with the two minions.
- The commercial for O'Hare involving bottled air. "Please breathe responsibly."
- A background funny moment in the opening song, during the lyrics "We thank the lord for all we got." there's an small man wearing an umbrella hat holding a foldup tanning sheet. He's clearly looking at the two women on either side of him and once it blurs on him he backs up and his eyes shift from woman to woman.
- Just before the Once-ler hits it big:
- Lorax:"I'm playing poker, he's playing go-fish, and I think he's hungry." *cue Swomee Swan chick eating one of the fish's cards*Fish: Awww (in the most ridiculously cute voice imaginable)
- When the Once-ler tells the second part of his story, it cuts to a scene at night with the fish swimming. One jumps and eats a firefly. Its eyes start to shine like flashlights, scaring the two other fish when it looks to them.