A character who held prominence in
comic book titles published by
DC Comics in the late
1960s through early
1980s.
His origin goes something like this: When Wally West was about twelve years old, his uncle Barry Allen set up an "accident" which splattered electrically-charged chemicals all over Wally's body, thusly gaining the power of super speed and becoming one of a select few speedsters in the human race, along with Jay Garrick, Johnny Quick, Jesse Quick and a few others. As Barry Allen was at the time The Flash and second man to carry the title Fastest Man Alive, Wally became his sidekick -- Kid Flash.
Wally felt used and tricked by his uncle when he learned the accident was set up on purpose, and always felt a level of resentment for his uncle until near the end of their teamwork together. He originally wore a smaller duplicate copy of his uncle's red costume, but then switched to a flashier yellow suit and left Barry Allen's side, opting instead to join the Teen Titans. He worked with them off and on for many years (consequently more years than he could feasibly be a teenager, but comic book time works a bit differently than real time). He quit more than once, feeling the reluctant hero. After he left the first time, he was coerced into returning to the Titans by a mysterious empath named Raven who played with his mind and emotions and made him fall in love with her. Needless to say when he came back to his senses that just ticked him off even more.
Eventually he got tired of the superhero game completely, and once again hung up his yellow Kid Flash outfit. Opting instead to try and be Wally West for awhile, and explore a possible romance with a lass named Frances Kane. He also learned that using his superspeed was slowly killing him, due to a rare disease which had no known cure.
During the Crisis on Infinite Earths, Barry Allen turned up missing, and Jay Garrick asked Wally to wear the Kid Flash costume one final time, to help him open a door between their reality and an anti-matter universe in which stood the Anti-Monitor, one of the most dangerous villians ever known. Despite the fact it could kill him, Wally opted to assist, considering the lives of five universes were at stake. During their battle with the Anti-Monitor, a random shot of energy altered Wally's molecular structure, putting the disease which killed him into remission. However, he was unable to travel faster than the speed of sound for a long time, and also aquired some other side-effects which eventually hammered themselves out.
Barry Allen was forced to race a tachyon particle in order to save the universe and upon Barry's death, Wally hung up his yellow outfit one last time and put his uncle's costume on. Ever since 1985, Kid Flash has been no more: now Wally West is the New Flash.