There's a reason zookeepers usually use sedation.
It's a short book. It's kind of about understanding that other people might be feeling the same way as you are, a kind of empathy. There's a crocodile who visits the dentist and gets a cavity filled, and then leaves. The way that the book is presented shows that everything the crocodile thinks or says is thought or said by the dentist as well. For example, "I must be brave" or "Thank you so much. See you again next year." Neither one of them really wants to do this. The crocodile doesn't want to go to the dentist, and the dentist doesn't want to treat the crocodile. They're both afraid of each other, but have this relationship where they both benefit by it.
I'm not crazy about this book, but I like the way the idea is presented: both of the characters feeling the same way about each other but being brave or not wanting to get angry. It seems like it would help children understand the concept of empathy, and the idea that 'he's just as scared of you as you are of him.' On the other hand, it might also cause them to become afraid of dentists, but I guess it's kind of cliche that everybody's afraid of the dentist. But the parent can explain to the child that the reason the crocodile doesn't want to go to the dentist is because he hasn't been taking care of his teeth. If the crocodile had been taking care of his teeth properly, both he and the dentist probably would have had a much better experience.