The Lorax

The Lorax is a story written and illustrated by Dr. Seuss that was first published in 1972. It is an environmentally-oriented story about a person named Once-ler (shown only as a pair of arms) who caused devastation to the land and was constantly scolded for it by a creature called the Lorax, whose warnings the Once-ler had ignored until it was too late.

The Lorax was adapted into a TV special in 1972 by DePatie-Freleng Enterprises and featured Eddie Albert and Bob Holt as the voices of the two main characters of the story. A feature-length film from the producers of Despicable Me was released in 2012, with Danny DeVito as the title character.

Tropes used in The Lorax include:

Aesoptinum: Truffula trees. You know, the ones for which The Lorax speaks. They're used for making Thneeds.
Ambiguously Human: The Once-ler, though only in the sense that you never see any uncovered part of him.
Based on a True Story: Sort of. While on vacation in Africa, Seuss was charmed by some strange trees that he, being Dr Seuss, decided to call "Truffula trees". He was later shocked to see them being cut down. It inspired this story, with the Lorax being his Author Avatar.
Bittersweet Ending: Depending on your interpretation. See Downer Ending below for details.
Black and White Morality: Played straight in the original story, with the Lorax being white and the Once-ler and his family being black. The situation of the story is portrayed less so in the Animated Adaptation - at one point, the Once-ler argues with himself about what he is doing, ultimately justifying his actions by claiming that if he didn't do it, someone else would, and points out that shutting down his factory would cause all of his workers to lose their jobs; the Lorax admits that he has a point, and also that he himself wouldn't know the answer.
- A possible answer to this is that the Once-ler could've repurposed his factories for something more useful to society, and not so destructive, setting an example for future generations to follow, or to replant truffula trees to replace what they cut, like the real logging industry does nowadays.
Bowdlerise: The Lorax's line "I hear things are just as bad up in Lake Erie" was removed from the book in 1985 after two research associates from the Ohio Sea Grant Program wrote to Seuss about the clean-up of Lake Erie. However, the line is kept in the 1972 TV version (it is spoken by one of the Humming Fish), even in the VHS and DVD releases.
Dark Reprise: The TV special has a whole bunch of these as everyone leaves the land.
Determinator: The Lorax gets a speech that illustrates this well in his book's 1972 Animated Adaptation.

I speak for the trees! Let 'em grow, let 'em grow!
But nobody listens too much, don't you know?
I speak for the trees, and I'll yell and I'll shout
For the fine things on Earth that are on their way out!
They say I'm old-fashioned, and live in the past,
But sometimes I think progress is progressing too fast!
They say I'm a fool to oppose things like these,
But I'm going to continue to speak for the trees!

Downer Ending: The story ends with the forest gone, the animals gone, the settlers gone, the city gone, the factory gone, and the Lorax gone. Only the Once-ler remains, who regrets his actions. However, there is one ray of hope: UNLESS. If the boy can regrow the forest and protect it, maybe the Lorax will come back.
Egopolis: In the animated version, a town springs up around the Thneed factory, with everything named after the Once-ler ("Onceler Hills", "Onceler Burgers", etc.) There's an Our Founder statue labeled "To Our Beloved Once-ler", but it only consists of a giant hand holding a sign reading "Thneeds".
The Faceless: The Once-ler and his family.
Forest Ranger: The Lorax.
Greed: Pretty much the cause of the Once-ler's actions, especially when the Thneeds start to take off.
Green Aesop
Harsh Life Revelation Aesop: As the Onceler tells the boy who comes to visit him, when no one cares about others, there are dire consequences. Or, as he puts it, "Unless someone like you cares an awful lot, nothing is going to get better, it's not." The titular character tried to convince the Onceler to not cut down the Truffula trees to make Thneeds because it would hurt the wildlife, including the Humming Fish that choke from the factory fumes. In the TV adaptation, the Onceler keeps saying what is the harm in cutting down one tree, and later justifies that he has to keep making Thneeds so his employees will still have work. Eventually there are no more Truffula trees, the Lorax leaves, and the Onceler's fortune goes up in smoke as his family leaves and he has to shut down the factory. The Onceler was able to save one Truffula seed and gives it to the child, asking him to care and rebuild the forest. It won't be easy, given the TV adaptation states it will take ten years for the seed to sprout and ten more for it to become a sapling, and one tree by itself can't become a grove. But someone has to try.
Heel Face Turn: Nearly happens in the TV special following the Once-ler's second Ignored Epiphany (see below). But then, it's averted, hard, when the Once-ler's secretary informs him that the price of his company's stock had gone up more than $27. At that point, he goes into his tirade.
Heel Realization: The Once-ler in the end after the forest's destruction. By the time the boy visits him, he's had plenty of time to reflect on his mistakes.
He Who Must Not Be Seen: The Once-ler and his family (until the film adaptation).
Hope Spot: The Once-ler managed to save one Truffla seed and gives it to the boy who was listening to his story. Telling him to plant it and start a new forest in the hopes the Lorax and the animals that once lived there will come back.
How We Got Here: The story starts and ends at the place where the Once-ler's Thneed factory once stood, and the Once-ler explains to the boy how it all happened.
Ignored Epiphany: The Once-ler does this twice in the 1972 Animated Adaptation of this story. Once when the Bar-ba-Loots were sent away, and again when the Swomee Swans and Humming Fish leave. The latter instance segues into his rant from the climax of the book.
- In the 1st case, he reasons that someone else would do what he's doing so it wouldn't matter either way. In the 2nd, it looks like he's finally gotten the message and is about to turn around. But his secretary had the bad timing of informing about his rise in stock, triggering his greed.
Informed Ability: In the animated special, the song "Do Do Need a Thneed" lists a number of uses for the Thneeds, including a hammock, a toothbrush holder, a nest, an addition to soup, a grooming item, a dust cloth, a rust remover, a windshield wiper, a viper trap, a tobacco substitute, and a baby's diaper. We never see them used in any of these ways.
- Subverted when we see the first Thneed, as it visibly changes into a shirt, a sock, a glove, and a hat. Off-screen, it also turns into a pillow and a blanket.
Look on My Works Ye Mighty and Despair: Before the events of the story the Once-ler and his relatives ran a lucrative, though highly destructive, business turning the foliage of the Truffula Trees into Thneeds. When the last(?) Truffula Tree is felled, however, the Thneed factories shut down and the Once-ler's relatives leave for new ventures. By the time the story begins, all that remains of the forest is a field of tree stumps, the ruins of the Thneed factories, wild weeds (call Grickal Grass) growing, and the Once-ler himself.
Meaningful Name: The Once-ler.
The Musical: The TV adaptation.
My God, What Have I Done?: The Once-ler, as he has seen the results of his deforestation efforts.
Nature Spirit: The Lorax.
Never Trust a Trailer: The trailers never bother to tell you that the TV version is a musical with full, three-minute musical numbers.
Once-lers Are Bastards: They're pretty much the stand-in for humans in this story. They consume the territory of all its Truffula Trees and then move on when there is no more, leaving the once flourishing land a deserted polluted mess. (This is made more explicit in the film, where the Once-ler is a human.)
Scare'Em Straight: The entire point of the story is to do this.
Sugar Bowl: The land started out as this...
- Sugar Apocalypse: ..and became this.
Tempting Fate: The Once-ler does this near the end with his rant how he'll just keep growing and growing his company (it's quite jarring in the animated special as he sounds like a madman) right before the final Truffula Tree is cut down. With no trees, there's no way to make Thneeds, and his company goes broke not long after.
Villain Protagonist: The Once-ler.
Voice for The Voiceless: The Lorax, who speaks for the trees.