Harry Potter has a scar, Frankenstein's monster is stitched together from body parts, Oedipus is a cripple and yet all these characters with physical flaws and disabilities were capable of great things and had heroic qualities. This may be to make the character more interesting or as a plot element but another possibility is that the physical flaw or disability is symbolic.
If a physical flaw is symbolic then any character with a physical flaw should be studied carefully as the symbolism may allow for deeper analysis of the character. At the simplest level the symbolism may simply be that the character is different from others around them but when the actual disability is looked at the symbolism and deeper meaning can be found. For example a physical scar on Harry Potter could be interpreted as being scarred mentally or emotionally as well. Or in the case of Quasimodo, the hunchback of Notre Dame the physical flaws show difference but also form a deeper symbolism. Although Quasimodo has the body of a monster but is kind and although the people who surround him have reasonably perfect bodies many of them are cruel and possibly monstrous adding an irony that would not exist without the physical flaws of Quasimodo. In Frankenstein by Mary Shelley there is a similar theme of monstrosity and the monster has a monstrous body and is different but is not necessarily the true monster of the story.
Furthermore, the physical flaws that the characters have are commonly more than symbols; they are very often plot points where the character's flaw affects their decisions and drives the story forward making a physical flaw even more interesting and important. For example in Frankenstein, Frankenstein's Monster murders multiple people not because he is a monster but because his deformity causes people to reject him and that rejection creates anger which leads him to kill. In Harry Potter, Harry is attacked by Voldemort as a baby and decides to destroy Voldemort not because of a prophecy or through hate but because he has experienced the destruction that Voldemort has caused and wants to stop others suffering in the same way.
If a physical flaw is symbolic then any character with a physical flaw should be studied carefully as the symbolism may allow for deeper analysis of the character. At the simplest level the symbolism may simply be that the character is different from others around them but when the actual disability is looked at the symbolism and deeper meaning can be found. For example a physical scar on Harry Potter could be interpreted as being scarred mentally or emotionally as well. Or in the case of Quasimodo, the hunchback of Notre Dame the physical flaws show difference but also form a deeper symbolism. Although Quasimodo has the body of a monster but is kind and although the people who surround him have reasonably perfect bodies many of them are cruel and possibly monstrous adding an irony that would not exist without the physical flaws of Quasimodo. In Frankenstein by Mary Shelley there is a similar theme of monstrosity and the monster has a monstrous body and is different but is not necessarily the true monster of the story.
Furthermore, the physical flaws that the characters have are commonly more than symbols; they are very often plot points where the character's flaw affects their decisions and drives the story forward making a physical flaw even more interesting and important. For example in Frankenstein, Frankenstein's Monster murders multiple people not because he is a monster but because his deformity causes people to reject him and that rejection creates anger which leads him to kill. In Harry Potter, Harry is attacked by Voldemort as a baby and decides to destroy Voldemort not because of a prophecy or through hate but because he has experienced the destruction that Voldemort has caused and wants to stop others suffering in the same way.
Harry Potter and the Philosopher's Stone illustrates the concept perfectly. Pay attention to the scar (visible at 1:04) and the "I think it is clear that we can expect great things from you" (also a nice shots of everyone's favorite potions teacher at 1:06 and 1:41).
References:
'Thomas C. Foster, 2013. How to Read Literature Like a Professor: For Kids. Reprint Edition. HarperCollins.'
'Title Image: 'http://images5.fanpop.com/image/photos/27500000/Harry-Potter-and-the-Order-of-the-Phoenix-BluRay-severus-snape-27573978-1920-800.jpg'
'Thomas C. Foster, 2013. How to Read Literature Like a Professor: For Kids. Reprint Edition. HarperCollins.'
'Title Image: 'http://images5.fanpop.com/image/photos/27500000/Harry-Potter-and-the-Order-of-the-Phoenix-BluRay-severus-snape-27573978-1920-800.jpg'