The Old Convict

Freeman plays "Red" Redding, a lifer who knows the ropes at Maine's "Shawshank State Prison."

—From the back cover of the case for the DVD of The Shawshank Redemption

You'll find him in just about every prison film and television series ever made. He's the old convict that's been inside as long as anyone can remember. He knows everything there is to know about how the prison works, and can explain it to new inmates. He tends to have the respect of most of his fellow inmates (except maybe the Ax Crazy psychos).

If the central characters decide to break out, The Old Convict probably won't go with them, realising he no longer knows how to survive in the outside world. He may die at the hands of the authorities or vicious fellow inmates (maybe in an attack actually aimed at the hero), inspiring the heroes to either escape or seek vengeance.

Only occasionally related to The Con or the Con Man.

Examples of The Old Convict include:

Comic Books

Ben 99 in the 2000 AD serial Harry 20 on the High Rock. Seemed more than a little stir crazy. Turned out not to be what he seemed, in more ways than one.

Fanfic

Wyoming in the Red vs. Blue fanfic Murderer's Row.

Film

Ellis Boyd "Red" Redding from The Shawshank Redemption.
- Also Brooks, though he doesn't seem to be quite as prison-savvy as Red. Or at the very least, it's not as obvious.
Pop in the original version of The Longest Yard.
- Doc in the British remake, Mean Machine.
Fergus Wilks (David Kelly) in Greenfingers.
Coach in Death Race.
English from Escape from Alcatraz
Over the course of the film Life (Eddie Murphy & Martin Lawrence) the two characters become this over the course of decades of incarceration.
Slammer in Micmacs, who introduces himself by saying that he's been in prison for 3/4ths of his life. He uses his status as an old-time prisoner to distract some drug dealers long enough for Bazil to steal their heroin.
Cresus in Prison.
Frank Perry in The Escapist.

Literature

'Low Key' Lyesmith in American Gods by Neil Gaiman.
Older Than Radio: Abbe Faria in The Count of Monte Cristo by Alexandre Dumas (and its various film and television adaptations).
General Jan Dodonna in The Krytos Trap serves this purpose for the captured Corran Horn in Ysanne Isard's Lusankya prison. Though he doesn't go not because he doesn't know what to do, but because he's the highest-ranking Rebel prisoner, knows they can't get the other Rebels out, and also knows that if he escapes without them she'll have them killed.
In Donald Westlake's Help, I Am Being Held Prisoner!, the protagonist is an inveterate practical joker who is in jail after a prank gone wrong. His Cellmate is an archetype old con provider of good advice.
Babe Fraser in The Stars' Tennis Balls by Stephen Fry.

Live Action TV

Bob Rebadow in Oz. Despite his delusions, Rebadow seems clued into everything that goes on in Oz.
D.B. Cooper, alias Charles Westmoreland, in Prison Break.
Fletcher in Porridge. Although Fletch has been in and out of prison his entire life rather than spending most of it inside serving a single sentence, he still fulfills the role of explaining the system to newcomers.
- And even ended up doing so in real life.
- A more conventional Old Con is the very ancient Blanco. When we first see him, he's completed a replica of Muffin the Mule in the prison workshop: "You know, him what's on television." (Muffin the Mule was broadcast from 1946 to 1957. The Porridge episode was broadcast in 1975.)
Francois Villars in the MacGyver episode "The Escape".
When Earl is in jail in My Name Is Earl and looks for a gang to join, he finds that the Old Con gang aren't any more adapted to survival inside the prison than anyone else.

Video Games

Eddie Gordo's backstory from Tekken 3 is that he was framed by the Mishimas, and while in prison, was trained in Capoeira by the oldest convict interned there. Christie Monteiro is the old man's granddaughter.
In The Chronicles of Riddick: Escape From Butcher Bay, Riddick encounters an old prisoner in the Single Max section, who among other things asks Riddick what his first kill was like ("that's between me and him" being the answer"), and offers Riddick a reward if he gets rid of a troublesome inmate. In a Shout-Out to The Shawshank Redemption, he's named "Red".

Web Comics

Doyle in The Lydian Option describes himself as the "welcoming committee" - a human who introduces new human prisoners to life in the alien prison and shows them the ropes.
Ian Starshine fills this role at the gladiator camp in The Order of the Stick; his reference to being nicknamed "Red" is a Shout-Out to The Shawshank Redemption.

Western Animation

Chatter Telephone in Toy Story 3.
'The last registered Democrat' who helps the Simpsons escape the government re-education centre in The Simpsons episode "Bart-Mangled Banner".