Anthony, the Perfect Monster (I Can Read It All By Myself Beginner Books Series) by Angelo DeCesare, Angelo De Cesare
Illustrated in full color. Anthony always does everything he's supposed to, from eating his spinach to wearing his raincoateven when it's not raining! Then one day, Anthony cracks from the strain and, with one hiccup, becomes a horrible monster who rants, raves, and won't wear his raincoat no matter how nicely he's asked. When he turns back into a little boy, Anthony discovers that his family and friends still love him, because whether he's a perfect kid or a perfect monster, he's always perfectly himself.