King's novella is told from the perspective of Red, as he recounts the events leading up to the amazing prison break. Andy is the most well described character in the tale: "When Andy came to Shawshank in 1948," Red details, "he was 30 years old. He was a short, neat little man with sandy hair and small, clever hands ... He always looked as if he should have been wearing a tie." Red further describes Andy as "weak-looking," which makes him a target.
By 1963, as Andy is getting Shawshank's prison library going, Red notes that suddenly, "there were lines in his face and sprigs of grey showing in his hair. He had lost that little trace of a smile that always seemed to linger around his mouth." Come 1967, Red describes Andy as having "grown harder," in spite of the fact that Andy continued "wearing his freedom like an invisible coat." This vibe, Red explains, springs from the fact that Andy holds tight to the knowledge of his innocence.
The biggest difference between book Andy and movie Andy is their size. In the novel, Andy has a tiny frame that allows him to crawl through the pipes more easily. In the film, Tim Robbins' massive 6'5" frame isn't made note of at all, even though it makes it even harder for him to escape Shawshank the way he does.
