Kristen Bell wanted to create a heroine who is "flawed and goofy" for 'Frozen'.
The 33-year-old star voices Anna, princess of Arendelle, in Disney's animated film which was director by Chris Buck and Jennifer Lee and the filmmakers insist the actress shares similarities with her alter-ego.
Talking to empireonline.com, Lee said: "She came in to audition and she set the bar so high. She has a warmth to her and also a beautiful singing voice, which a lot of people don't realise.
"She's so funny and so smart, and there's so much of her in Anna. And like us, she wanted to create a heroine who's flawed and goofy and yet who's still inspirational."
Lee - who also penned the screenplay - admits she wrote the characters with particular stars in mind and found it easier to complete the script when she knew who'd been cast in the adventure.
She added: "She was a great partner. And the same with Jonathan Groff. They both really gave us the character's voice. I found I could write the roles much more easily when they were cast."