Has anyone else read The Riddle-Master trilogy by Patricia McKillip? There are several very-very-old (though not unkillable) characters in those. My favorite - he is indeed one of my favorite characters in all fantasy fiction - is Deth, the High One’s Harpist.
What about** God**, in the Holy Bible. I admit he’s only fleshed-out in part of the story.
About time. I was going to have to make that lame joke myself the way things were going.
Someone mentioned him earlier, and he bears closer examination: Casca the Eternal Mercenary in the novel series (20+ volumes) by Barry Sadler.
Casca Rufio Longinus spears JC on the cross and a drop of Jesus’ blood falls on his hand. Without thinking, he wipes his hand across his face and winds up getting the blood on his lips and ingesting it. The blood makes him immortal.
In one of the novels, he has made it to the Aztec empire and winds up getting his heart cut out as a human sacrifice. He then stands up, grabs the heart and sticks it back in the hole in his chest. I’d say that’s pretty fleshed-out. 
Octavia Butler has a couple of females who are at least very long-lived if not immortal.
Kage Baker has Menendez the Botanist who is definitely and without any question immortal (unless the Company grants her wish in the next book).
[highjack]I really struggled with that, but I may have to try it again. I loved her The Forgotten Beasts of Eld.[/highjack]
I’m suprised no one has mentioned Michael Moorcock’s Eternal Champion. Doomed to maintain the balance between Law and Chaos in Moorcock’s Multiverse, the champion show up in many forms, one of the more noteable ones being Elric.
Along with the Champion is Jhary-a-Conel, the Eternal Companion. Friend of the Champion, he too shows up in multiple incarnations, generally aiding the Champion in his (or her, depending on the incarnation) aims, sometimes even leading to the Companion’s death (well, more appropriately, that incarnation of the Companion). Occasionally the Companion has to fight against the Champion.
Another good one I forgot about: Clifford D. Simak has a short story called “Grotto of the Dancing Deer”, about an archaeologist who uncovers some Neandertal cave paintings, and subsequently discovers that his assistant is the original artist. The Neandertal is about as well-fleshed as any character can be, in a short story.
There is the character in A Canticle for Leibowitz, who has survived the nuclear war, and lives on for the rest of the book–about 2000 years.
( He speaks biblical Hebrew, and is identified as the “old Jew”–but I never understood what purpose he serves in the book)
Octavia Butler’s book Wildseed, has two immortals as the main characters. Both of them can be both male and female.
Doro, who was born a male, is basically a spirit that jumps from body to body. He can do it at will or will do it if the body he is in is killed or hurt.
Anwyu, is born a female, but has the ability to shape change. To die, she would have to be vaporized. If she has a split second to react, she can instantly heal herself of any injury. Plus she has the ability to analyze and neutralize poisons in her body.
This book takes place between the end of the 1600s to the middle of the 1800s and then these two come back for the next book Mind of My Mind which takes place in the 1980s.
And as for DC Comics, there is Superman, Captain Marvel, The Martian Manhunter, The Gaurdians, The Zamorians, The Phantom Stranger, The Demon, Immortal Man, Vandal Savage, etc. etc. etc.
In the Trigun comic:
Vash dies slowly every time he uses the Angel Arm, as evidenced by his hair going from blonde to black.
The anime is silent on this matter.
My favorite immortals, or at least characters who are damn hard to kill:
*Xelloss, Slayers Next
*Alucard and Alexander Anderson, Hellsing
I thought there were a couple incarnations of the Jew, each being distinct from the other. The implication is that while each is long lived and act very similar, they aren’t the same person. Granted, it’s been a while since I read the book, so my memory’s a bit hazy, but I’m pretty sure that in the second age of the book, the Jew mentions how some think he is the same one who hung around in the first age of the book, but he maintains that he isn’t.
Some interpretations believe the Jew is a representation of the immortal “Wandering Jew” legend, where a Jewish man taunted Jesus on the way to crucifixion and Jesus told him to go on forever until Jesus returned. So he’s doomed to walk the world until the second coming.
But I’m still pretty sure it’s multiple versions rather than the same guy.
Ignoring Woodrow Wilson Smith and family, mentioned in the OP, may I suggest Poul Anderson’s The Boat of a Million Years: nine characters (and one brief chapter about a tenth, from Norse mythology), all very well fleshed out, who have indefinite lifespan.
No kidding? I stopped reading the series after, I think, the second book where the main character lives in an alien cocoon and emerges all-powerful. I was pretty sure, at that point, Feist had no plan for the series; he was just writing the first thing that came to mind.
But wandering Jew aspect sounds interesting–even if sillier than the first two books I read.
Has anyone mentioned Nathan Brazil from the Well of Souls?
Hoopy I’m glad you mentioned Michael Moorcock’s characters, he even has an imortal city Tanelorn. Another emortal people havn’t mentioned, though more a popular than fleshed out character is Marvin the Paranoid Android.
Of course, since Amber is near the heart of things, there is likely a close enough shadow to make the whole question rather moot (if I remember my readings correctly). It seems there should always be another shadow just a little bit closer than the one you’re in, without actually reaching amber, and that there would reside in it a close enough simulacrum of each of the Amberites as to make them essentially immortal. At least, until the forces of Chaos mess everything up.
Back to the point of the post, though…
Diana Wynne Jones has created some interesting immortal charcters in Luke and Mr. Wedding from ‘Eight Days of Luke’, the seven siblings in ‘Archer’s Goon’, and the Magids (not technically, but close enough to count) from ‘Deep Secret’ and ‘The Merlin Conpiracy’.
Koschei the Deathless. Not fleshed out, but hinted at to intense effect.
Zelazny’s Immortal’s companion (brain blank on both names), tells him what’s about to happen, he disregards it each time, and she’s right each time. It’s a minor riff that vanishes amongst all the action and stimulus in that book. I’d say she first showed up in ancient Greece when she had a difference of opinion with Apollo.
Oooh, oooh, oooh! Mista Kotta! Mista Kotta! I goy one!
Asprin’s character Aahz, the pervert – excuse me, Pervect – from the Myth series.
Tied to a bedpost for eternity. Geez.
Does the Frakir lose its magic on the bedpost at night?