One of the most interesting characters out there, in my opinion, is Princess Fiona from Shrek. I love the original Shrek movie, because it turned the traditional fairy tale on its head. Let's look at Fiona through the lens of characterization. How does she appear on the outside?
At the beginning of the movie, Fiona is a princess in an ivory tower, protected by a fierce dragon. She's been locked up for years (poor thing) and has very definite ideas about what will happen when she's rescued. The man who saves her from her incarceration will be: A handsome prince. He'll give her 'true love's kiss'. They'll marry, and live happy ever after. And on receiving true love's kiss, she'll banish the ugly part of herself that appears each night.
She's gorgeous. Tall, slender, and pretty. She's princessy, haughty, and proud. She'd be your average fairytale princess if her deep character matched her characterization. But it doesn't. Princess Fiona (like an onion) has layers. And once those layers are revealed, she becomes much more than just a princess, she becomes real.
I love the movie Shrek, because not only can we see that Fiona is a deeper character than intitially thought, we can see it by her revealing her true self (spoiler alert: an ogress!!). But in her human form, she acts in many unexpected ways that tip us off to her true nature. She loves all sorts of inappropriate for a princess behaviour. Eating rats on skewers, calmly frying eggs when her singing causes the bird mother to explode, general farty and belchy behaviour, and joking around with Shrek, who she has a lot in common with. She's ashamed of her ogre transformation, hiding at night so that she can't be seen. She feels she cannot be loved for who she is, a trait she also shares with Shrek.
When Lord Farquar finally claims her as his bride, the opening shot of him climbing from his horse and being tiny is yet another disappointment to her. He hasn't battled the dragon and fought for her. He's not amusing, like Shrek. And, if she were in any doubt, Fiona realises that characterization is not true character. Farquar isn't her true prince. Who knew her prince would be an ogre?
So appearances are deceptive. What is inside matters far more than the externals. And only by accepting that, and learning to love her true nature, does Princess Fiona achieve true love.
And I think she looks gorgeous green!