Displaced Origin

Whenever the original instance of a character in a series gets obscured by later developments of the same character, whether it be a sequel, an adaptation, the casting of a breakout character, even a Retool of the original. In the most extreme cases the original installment hardly gets recognized by anyone but the most hardcore fans.

Possibly a supertrope of both Sequel Displacement and Adaptation Displacement. The exact inverse of First Installment Wins.

Anime & Manga

 * The Yu-Gi-Oh manga started out as the tale of a teenager whose dark side brings judgment on abusive people with lots of Nightmare Fuel. Halfway into the series the card game took over and everything from that point onwards became the tale of people beating each other in a Serious Business card game.
 * Anyone remember when Bulma was one of two main characters in Dragon Ball?

Comic Books

 * Marvel Comics has several examples:
 * Captain America is almost synonymous with The Avengers, despite the fact he predates them by twenty-two years and wasn't a part of the team's original roster.
 * Wolverine's origins as a Hulk villain are hardly ever mentioned anymore, if at all.
 * The villainous origins of Quicksilver, the Scarlet Witch, and Hawkeye have pretty much been swept under the rug.
 * It's not so much that anyone has forgotten that Quicksilver started as a villain, as that he is best known for his Heel Face Revolving Door tendencies.
 * Mary Jane Watson is regarded as Spider-Man's true love, despite her original role as The Veronica.
 * Originally, Tintin did some reporting, but by the fourth or fifth book, he seemed to have surreptitiously retired to the quiet life of getting swept up in fantastic adventures and foiling the plots of mustachioed movie moguls.

Film

 * H.P. Lovecraft's famous Mad Scientist Doctor Herbert West was described in the original pulp serial as blonde-haired and blue-eyed. Ever since the film adaptation of Re-Animator came out, however, just about every subsequent depiction of West in any other work made his appearance much closer to that of actor Jeffrey Combs.

Live Action TV

 * Saved by the Bell. Nobody remembers Miss Bliss, and nobody cares either.
 * Similarly, few people remember that once upon a time, The Facts of Life featured girls named Molly, Nancy, Sue Ann, Laura, and Jennifer in addition to Tootie, Jo, Blair, and Natalie.
 * The Fonz from Happy Days was originally conceived as an intimidating, occasionally violent tough-guy semi-villain and semi-criminal. Cue the Flanderization.
 * Laverne and Shirley were... shall we say... portrayed as "easy" girls when they first appeared on Happy Days. And violent. Especially Shirley.
 * Mork from Ork was originally a villainous alien invader intent on destroying the Earth in his first appearance on Happy Days.

Music

 * Singer Julio Iglesias became a musician after a car crash. Before the accident he was Goalkeeper for the Real Madrid Youth Team.
 * Ringo Starr is well known as The Beatles' drummer. Not many people remember his early fame as Rory Storm and the Hurricanes' Drummer.
 * The Beatles' (also known as "The Fab Four ") early incarnation as a Five-Man Band.

Western Animation

 * U.S. Acres. On the strips Orson started as a small piglet and grew up with the time learning important lessons along the way. On the animated shorts Orson is a mature Pig and the wisest character, often teaching important lessons to young chicks Booker and Sheldon.