Ultimately, this is a story about manipulation and cruelty. Horton is a kind elephant who lives in the jungle, and is approached one day by the cruel Kwuggerbug. The Kwuggerbug offers Horton the chance to eat some delicious Beezlenuts and all he has to do is take the bug there. Horton accepts, believing that this deal with benefit the both of them.
Firstly, the Kwuggerbug tells Horton that he must travel across the crocodile-infested lake, which Horton is at first wary of. However, when Horton is reluctant the bug reminds him of their deal and manipulates him into continuing. The bug then tells Horton to climb up a mountain, which hurts and bruises the poor elephant. All the while, the Kwuggerbug is sat safely on top of Horton, and does not seem to be contributing much.
When the pair finally reach the Beezlenut tree, the Kwuggerbug takes advantage of Horton one last time, before claiming that he will only share the beezlenut shells with Horton, while the "meat" is his. As such, this story is an allegory about unfair deals and the fact that some people will try to manipulate others into doing all of the work for little reward. Thankfully, Horton needs to sneeze at the end of the story, which blows the Kwuggerbug away and teaches him a lesson.