Mayzie bird is a lazy bird, and would much rather be flying off to somewhere fun rather than tend to her egg. But when friendly (and gullible) Horton passes by her, Mayzie sees her chance to grab a little R & R in sunny Palm Beach. She convinces Horton to sit on her egg, a ploy that works despite Horton's concerns. Once gone, however, Mayzie decides "never" to go back to her nest again. Horton, stuck with the egg on his own, does everything he can to ensure it's safety. Through blizzard, teasing, capture, and seasickness Horton is faithful to his promise, "One hundred percent". When the egg finally hatches (and Mayzie insists on claiming it once the work has been finished) the result is a surprise and delight to the patient elephant.
There's a lot to love in this old story. The Seussian rhyming schemes (often parodied but rarely equaled) have the perfect amount of syllables per line. Every page scans easily, and you cannot help but hear the words spoken in your brain as you read them. I remember growing up in Kalamazoo, Michigan as a child and delighting at the reading of the places Horton travels (ala circus) that mentioned my own rhymable home town. Such lines are coupled with the fabulous illustrations that show every minute of Horton's misery in wrenching detail (though not so much that you ever think the elephant is under too serious duress). Thus the payoff at the end is even better than you could hope for. It's amazing how memorable I find these illustrations, even now some twenty years later. There's something about Dr. Seuss that just connects with children on the deepest level imaginable. And there's something about "Horton Hears the Who" that deserves that connection.