I'm going to presume you already know that as a fictional character, you are making it all up.
Start thinking of the character as a friend, or an acquaintance if you don't particularly like the character. Imagine the person in various settings; imagine him/her nearby wherever you happen to be. How does the character act in this setting? Clothing? Language? How does the character treat people in that setting? Imagine the character's voice, mannerisms, back story, habits, love life, education, profession. What does the character do when alone? What thoughts and feelings does he/she experience? Motivations? Benevolent, brilliant, sleezy, calculated, scheming, cold/heartless...? Develop stories or themes about the character, even if they don't directly relate to the writing project the character is part of. You have to know the character intimately well before you introduce the person to the project. You can't just bring the character in and add convenient 'facts' as needed. That will be painfully obvious and you will have a very shallow character on your hands. Ideally, there should be more in your head about the character than you could possibly include in the project; you should have to pare down what parts of the character's story make it through.
Bottom line: You can't write about someone you don't know.
Harry Potter is a fictional character, you cannot write to him.
The character, Rose, in the movie Titanic, is a fictional character.
You can, yes, but she is a fictional character, so you might not get anyone to write back unless you have creative parents.
Athos - fictional character - was created in 1844.
No, he's a fictional character.
None. She is a fictional character.
Harry Potter is a fictional character, you cannot write to him.
Sherlock Holmes is a fictional character.
Yes, he was a fictional character.
The character, Rose, in the movie Titanic, is a fictional character.
'Nancy Drew' is a fictional character. She wasn't an author. She wrote no books.
You can, yes, but she is a fictional character, so you might not get anyone to write back unless you have creative parents.
Athos - fictional character - was created in 1844.
Zatoichi is a Japanese fictional character created by the novelist Kan Shimozawa. This fictional character is a blind masseur, gambler and a swordmaster.
No, he's a fictional character.
She is a fictional character.
pretent you are that character and write a resume' as you feel they would write it using their name and any other information about them from the book and then make up the rest like job history ect but make it fit their character