This section provides information on the variation of character interpretations both pre-Crisis and in iterations since Crisis. Focus is on characters defined by their given name (Alan Scott, Jay Garrick, etc.) rather than code name (Green Lantern, Flash). Emphasis is on interpretations where the character had a major role versus a cameo or non-essential story role to minimize clutter.
The Golden Age Robin
The origin of Dick Grayson’s career on Earth-One is thought to largely resemble his Earth-Two counterpart, albeit starting in the 1960’s instead of the 1940’s. He again is the ward of Bruce Wayne, taken in after the deaths of his parents who are performers with Haley Circus. He participates in much of the same early casework, encountering the Joker, the Penguin and other well-known adversaries of the Batman. One divergence in the early career of the Earth-One Robin was extensive work with the Earth-One Superman, who had a much tighter relationship with the Earth-One Batman after discovering each other’s secret identities early on (Superman #76). As a result, Robin was much more involved in the super-hero community in general from onset, unlike the Earth-Two history where heroes operated in relative isolation in their respective cities. As a result, he was one of the founding members of his own team of crime-fighters, the Teen Titans, joining together the second generation of heroes on Earth-One (Brave and the Bold #54).
As he approached adulthood, he left the Wayne household to enroll at Hudson University, where he remained for some years (Batman #217, Detective Comics #394). There he engaged in a series of low-level crime-fighting activities and became a frequent partner of Batgirl, secretly Commissioner Gordon’s daughter Barbara in disguise. He maintained activity with the Teen Titans until they disbanded (Teen Titans #53). He eventually dropped out of college and return the Wayne Household (Batman #330) and became a periodic partner to Batman but felt a growing need for his own identity. After re-forming the Teen Titans in 1980 (DC Comics Presents #26), he eventually abandons the Robin identity to adopt a new code-name as Nightwing (New Teen Titans #39). He remains active with the Teen Titans, becoming deeply romantically involved with team-mate Starfire and is a leader of the group during the Crisis on Infinite Earths. His future in this timeline is unrevealed.
The Robin of the Post-Crisis timeline Earth has a history similar to his Earth-One counterpart, this time with a career beginning in the mid-1970's. This version of Grayson had a more contentious relationship with Batman, leading him to adopt the Nightwing identity sooner in his career and taking a dim view of Batman’s tendency toward sidekicks in general, especially after Jason Todd is evidently killed by the Joker (Batman #426-429). As Nightwing, Grayson remained active with the Teem Titans (eventually evolving the name to just “the Titans” as the members grew into adulthood) though an arranged state marriage for Starfire (New Teen Titans Vol. 2 #17-18) and her infection with a “demon seed” eventually extinguished their relationship despite an attempt at marriage (New Titans #100). Over time, he eventually became more deeply involved with Barbara Gordon, who had assumed the role of Oracle in this timeline. Nightwing leaves Gotham and becomes the resident hero in the city of Bludhaven (Nightwing Vol. 2 #1) though he returns to Gotham when the city is destroyed by the Secret Society of Super-Villains (Infinite Crisis LS). Unlike Earth-One or Earth-Two Graysons, the version assumes the role of Batman when Bruce Wayne is evidently killed by Darkseid (Final Crisis LS) but surrenders it when Bruce Wayne returns from being sent back in time. Dick Grayson of this Earth remained active in the last recorded case pre-Flashpoint but his ultimate fate is unknown.
The Richard Grayson of this world has no relationship with Bruce Wayne at all, being a private citizen married to Barbara Gordon and father to son, John. They are among those who attempt to escape an Apokliptian assault that will ultimately destroy the planet but Barbara is murdered during the process and John is lost. He eventually finds his son, crossing path with the second Batman of this world, Thomas Wayne and with Wayne’s death, becomes the third Batman of Earth-2. He maintains the role as the survivors of Earth-2 colonize a new world until his killed the battle with the Ultra-Humanite (Earth-2:Society #21).
In various incarnations of Earth-3, a sidekick exists for Owlman known as Talon. Where backstory is available, Talon tends to align with the history of Dick Grayson, being the son of murdered acrobats (though in some reports the killer is Owlman). He eventually joins Owlman’s criminal operations but in the most complete reports, is eventually killed by the Jokester, Earth-3’s analog to the Joker (Justice League Vol. 2 #23.4: Secret Society). The current iteration of Owlman has a series of henchmen called Talons that may or may not human or even living beings (Crime Syndicate LS).
The Dick Grayson of this time line has a similar history to his Earth-0 counterpart, eventually becoming the hero Nightwing in Bludhaven. A divergence from Earth-0 occurs in this timeline where Bludhaven is evidently not destroyed as Grayson abandons the life of a costumed adventurer, marries and eventually becomes mayor of Bludhaven in the mid-21st century. While he had become somewhat estranged from Bruce Wayne, the re-emergence of the long-thought-dead Joker brings him into the Bat-Family again (Batman Beyond Vol. 6, #25-29). He is revealed to have a daughter, Elianna, who has her father’s spirit and steals a Batman uniform, starting a career as Gotham’s new Batwoman (Batman Beyond Vol. 6, #37).
Robin of Earth-21 was born in a similar time frame as his Earth-Two counterpart. He is known to be active until the 1950's but his ultimate fate has not been documented (DC: The New Frontier LS).
The history of this world’s Robin also largely resembles the history of his Earth-0 counterpart but in his middle age, he adopts a new identity – Red Robin, a fusion of his Robin identity with a darker Batman-esque appearance. He is somewhat estranged from Bruce Wayne as in other timelines and in this one, his marriage to Koriand’r of Tamaran (Starfire) was successful and they had a daughter, Mar’i. Grayson’s wife died of a vascular ailment and Mar’i grew into a rebellious vigilante with a mix of her mother and father’s style as Nightstar. When a nuclear explosion decimated Kansas following a battle of rogue metahumans, Superman re-activated the Justice League and Red Robin became a member, even tho Batman formed his own group, the Silent Cavalry. Robin survived the cataclysmic battle that followed as did Nightstar (Kingdom Come LS). He later reconciles with Bruce and helps Nightstar pursue life as a more heroic metahuman (The Kingdom: Nightstar). He outlives Bruce as he is seen at the latter’s funeral (JSA Vol. 3 #22) but his final fate is unrevealed.
Various Bizarro forms of Robin have been created or identified, named Bizarro Robin or Robzarro tho no long-term record of these forms exist and they may, like many Bizarro's not be fully stable.
In this timeline Robin is merged with the Ravager to form a new unnamed individual but whether this is Dick Grayson or not is known (Dial H for Hero Vol. 1 #10).