Santa Claus and Barbie are among some of the "most important characters" to have shaped society, behaviour - or even swayed the course of history.
Barbie is blamed for setting an impossible standard for beauty
Topping the list in a book of The 101 Most Influential People Who Never Lived is Marlboro Man - a 1950s marketing creation to boost cigarette sales.
The book's three US co-authors say that his biggest influence has been to cause the death of millions from cancer.
At number two is writer George Orwell's Big Brother, followed by King Arthur.
According to the book's authors, King Arthur - held by some to be a historical figure - embodies for many the ideal qualities of a monarch or leader.
Only characters that have managed to "shape society, change our behaviour, and set the course of history" made the list.
TOP 10 MOST INFLUENTIAL
1 The Marlboro Man
2 Big Brother
3 King Arthur
4 Santa Claus
6 Dr Frankenstein's Monster
8 Sherlock Holmes
9 Romeo and Juliet
10 Dr Jekyll and Mr Hyde
"The figments of our imaginations, the creatures we push out of our minds into the real world are fully capable of pushing back with surprising consequences," Jeremy Salter, one of the book's authors, told Reuters news agency.
Santa Claus registers at number four because he "makes us believe we are entitled to goodies just for living in an affluent society, and governs our entire economy for the last quarter of the year".
Characters such as the Ugly Duckling, Ebenezer Scrooge, Shylock and superhero Batman are also included.
Each entry is accompanied by a short description, explaining the significance of the character - be it good or bad.
Secret agent James Bond, positioned at 51, is praised for his "intrigue, sex appeal and British suavity with the highest technologies of modern age".
Meanwhile, Barbie - "the bodacious plastic babe" at number 43 - is blamed for "setting an impossible standard for beauty and style".