One of the oldest archetypes; a character that is noted for his or her ability to tell tales, or at least their propensity to do so.
Sometimes the tales have a purpose in the main plot. At other times it is simply an interesting side excursion, perhaps to give the setting a feeling of depth.
Sometimes overlaps with Miles Gloriosus and The Munchausen. Could conceivably be made to overlap with Intrepid Reporter.
For the Jim Henson series, see here.
Kitty Pryde in the classic X-Men issue "Kitty's Fairy Tale", made up a bedtime story for young Illyana Rasputin, casting herself as the heroine and other members of the X-Men as characters. Notably, Kitty cast Cyclops as a prince and Jean Grey as a princess cursed by the evil Phoenix, and gave the Scott and Jean in her story the Happy Ending their counterparts were denied.
Fairy Tales
In The Black Thief and the Knight of the Glen, the thief saves the lives of his companions by claiming to have been in more danger than they were, and the knight gives him their lives, one by one, to get the stories. The last story recounts how he saved the life of a baby, and the knight's old nursemaid assures him that it's true and he was the baby.
Conal Yellowclaw has the same plot, though he is the father of the men he's saving.
Also the two Intrepid Merchants in Ballad of the King's Jest by the same author.
Belgarath in The Belgariad has masqueraded as a traveling storyteller, and his storytelling abilities are genuinely good.
The Minstrel in The Last Hero, who is dragged along by the Silver Horde to chronicle their last great act of heroism. It is revealed at the end that he is only The Minstrel - no name other than that - and his entire purpose is to be the one that tells the tale. Despite his battered appearance by the end of it all, he seems to be a pretty good sport about the whole thing. Or else he has been driven insane by the ordeal and forgotten whatever name he had before.
Taleswapper (aka William Blake) from the Alvin Maker series
Sara Crewe in A Little Princess, as well as all the adaptations thereof. Especially notable in the Alfonso Cuaron film and in the anime, where her narratives are shown in detail, and become an important plot point.
The title character of The Book Thief, by Marcus Zuzak, finds she can calm people down by reading aloud to them during an air raid in World War II Dresden.
NUMB3RS : Interestingly enough Charlie Eppes, who constructs entertaining parables to illustrate math.
Gabrielle in Xena The Warrior Princess was a fantastic flair for storytelling before she became a full-fledged Action Girl and even taught Homer a thing or two.
In Norse Mythology, Odin has charge over riddles and poetry and runes and the like.
Anansi the Spider, who even challenged the gods (or Tiger, depending on the version you're reading), so that he would be considered king of all stories.
Her father loved me, oft invited me, Still questioned me the story of my life From year to year, the battles, sieges, fortunes, That I have passed. I ran it through, even from my boyish days, To th' very moment that he bade me tell it, Wherein I spoke of most disastrous chances, Of moving accidents by flood and field, Of hair-breadth ’scapes i' th' imminent deadly breach, Of being taken by the insolent foe And sold to slavery, of my redemption thence And portance in my traveler’s history.
Wendy in Peter Pan. The fact that she knows "lots of stories" is what makes Peter take her to Never Land in the first place, since the Lost Boys don't know any stories. In early drafts of the script, even the Indians listen in.
An episode of the X Men animated series puts Jubilee in this role. When she and a bunch of non-powered children are trapped in a cave, she cheers them up via telling them stories where she cast herself as an Action Girl, Gambit and Wolverine were her teammates, Professor Xavier was The Mentor...
Real Life
Scottish Clans will often have an official clan bard. In times passed this could be hereditary or perhaps a close relation of the chief. They would follow close behind the chief in battle to make sure the clan's glorious deeds were recorded. The clan's inglorious deeds were of course treated differently.