I would recommend to a modern day Frankenstein's Monster the following:
To Kill a Mocking Bird - so he understands ppl are predjudiced and not just against ugly stitched up monsters, but anyone who is different.
The Diary of Anne Frank - so he knows that hate that goes unchallenged can bring out the worst in humans.
Last, The Very Hungry Caterpillar is about a caterpillar who eats a variety of foods before becoming a butterfly.
@Bliss all very interesting choices and all books I have enjoyed.