A valuable lesson is presented here about the way to deal with prejudice, however irrational, especially in adults. Clearly, Lyle is the most lovable crocodile in the world, as any kid will tell you. And in this story, perplexed by the hate mail, he tries even harder to be sweet. Most interesting, it becomes clear that the problem lies with a mother who doesn't want her daughter to play with crocodiles, and says that "nice neighborhoods" don't allow them.
Bernard Waber keeps these complex issues child-friendly, and opens the discussion up for parents of kids who get it, but who aren't yet ready for more overt books about prejudice. Confusing the issue, though, is the fact that it is perfectly reasonable for a good mother to prevent her child from playing with a crocodile. Also, Waber again (as in Lyle, Lyle, Crocodile) resorts to the plot device of a melodramatic rescue to resolve the problem -- not a practical example to follow.