“Write what you know,” they say, so it makes sense that many authors take a good look at friends and family when creating characters for their books.

1. Huckleberry Finn

Mark Twain once admitted that he wasn’t terribly creative in creating Huckleberry Finn—he said he had shaped the character almost precisely on his buddy Tom Blankenship. From his autobiography:

"In Huckleberry Finn I have drawn Tom Blankenship exactly as he was. He was ignorant, unwashed, insufficiently fed; but he had as good a heart as ever any boy had. His liberties were totally unrestricted. He was the only really independent person—boy or man—in the community, and by consequence he was tranquilly and continuously happy and envied by the rest of us. And as his society was forbidden us by our parents the prohibition trebled and quadrupled its value, and therefore we sought and got more of his society than any other boy's."

Sadly, according to the editor’s notes in Twain’s posthumously published autobiography, Blankenship was repeatedly arrested for theft and died just five years after Huckleberry Finn was published.

However, in 1885, when Twain was asked if Huck Finn was “a creature of flesh and blood,” Twain responded, “Well, I could not point you out the youngster all in a lump; but still his story is what I call a true story. The incidents are, in the main, facts, and I tried to make a faithful painting of certain phrases of life on the Southern Mississippi.”

2. Dean Moriarty

When Jack Kerouac wrote On the Road, he was really writing about his own cross-country exploits with his Beat Generation colleagues. For example, the selfish Dean Moriarty represents Neal Cassady, close pal of Kerouac, Allen Ginsberg, Ken Kesey, and the Grateful Dead (among others). In fact, the character’s name is Neal in the original On the Road scroll. But that’s not the only character Cassady inspired: Kesey, Hunter S. Thompson, and Tom Wolfe all took inspiration from him.

The real Neal died at the age of 41 after being found comatose by a railroad track in Guanajunto, Mexico, in 1968.

3. Nora Charles

One of the wittiest female characters in literary history, Nora Charles from The Thin Man, doesn’t hold a candle to her inspiration, Lillian Hellman. Lillian was author Dashiell Hammett’s significant other for 30 years, but she was also a respected playwright, screenwriter, author, and outspoken political activist. Hammett apparently told Hellman that she was the inspiration for his female villains as well.

4. Miss Havisham

It’s almost hard to imagine that the furious and completely insane jilted bride of Charles Dickens’s Great Expectations has a flesh-and-blood counterpart. But she does—in fact, there are a couple of people who might fit the bill.

The first, Eliza Emily Donnithorne, was an Australian woman who thought she was getting married in 1856. When she was stood up by the groom, she refused to change anything about the house; the wedding feast even sat out until it rotted into non-existence. Legend has it that Donnithorne never left the house again.

Another potential inspiration was Madame Eliza Jumel, Aaron Burr’s second wife, may have gone a little mad in her desperate attempts to break into New York high society; after finally throwing a successful dinner party for Joseph Bonaparte, she supposedly left the banquet and place settings out for decades to commemorate her social acceptance.

5. Philomena Guinea

The wealthy Philomena Guinea of Sylvia Plath’s The Bell Jar was based on Plath’s own benefactor, Olive Higgins Prouty. Prouty was a novelist probably best known now for Now, Voyager.

6. Hester Prynne

The modest grave of Elizabeth Pain in Boston’s King’s Chapel Burying Ground holds a secret if you look at it closely. Some believe the A inscribed on the stone shows that she was “whipt with twenty stripes,” though it was for the murder of her child, not for adultery (she was found not guilty, by the way). The damning mark may have served as Nathaniel Hawthorne's inspiration for Hester Prynne in The Scarlet Letter. There’s also a record of one Hester Craford who was severely flogged for “fornication” with a man named John Wedg in the 1660s. At the very least, Hawthorne may have borrowed her name.

7. Beth March

As a neighbor of the Alcott family in Concord, Massachusetts, Elizabeth Hoar served as the model for Beth March in Little Women. Hoar was also good friends with Henry David Thoreau and Ralph Waldo Emerson, who liked to call her “Elizabeth the wise.”

8. Ford Prefect

Douglas Adams once explained that his Hitchhiker’s Guide to the Galaxy alien had done “minimal research” of Earth and thought he was choosing an inconspicuous name for himself because he “had simply mistaken the dominant life form.” The Ford Prefect, by the way, was a British car produced from 1938 to 1961.

9. Severus Snape

His name was almost as wizardy: John Nettleship. Rowling may not have enjoyed his classes very much, based on this description of Snape:

Snape is the very sadistic teacher loosely based on a teacher I myself had, I have to say. Children are very aware and we're kidding ourselves if we don't think that they are—that teachers do sometimes abuse their power and this particular teacher does abuse his power. He is not a particularly pleasant person at all.”

Nettleship wasn’t thrilled with the comparison when he found out about it, saying, “I knew I was a strict teacher but I didn't think I was that bad." He later came to terms with it enough to write a booklet called Harry Potter's Chepstow about various locations from Rowling's school days that may have inspired people and places from her successful series. Nettleship died of cancer in 2011.

10. Artemis Fowl

Eoin Colfer's little brother, Donal, was "a mischievous mastermind who could get out of any trouble he got into,” and seeing a picture of Donal in a dapper first communion suit reminded Colfer of a tiny James Bond villain.

For more fascinating facts and stories about your favorite authors and their works, check out Mental Floss's new book, The Curious Reader: A Literary Miscellany of Novels and Novelists, out May 25!

This post originally appeared in 2012.