Javelin - a decidedly obscure DC Comics supervillain, who was first introduced as an enemy of Green Lantern in 1984 - will be making an appearance in the 7th season of Arrow. It's unknown at this time if Javelin will be joining The Longbow Hunters villain group that is meant to be the main adversary of the upcoming season, or if he'll be an independent villain. In either case, the character seems like a worthy adversary for the vigilantes of Star City.
First appearing in Green Lantern #173, Javelin was never given a real name or a background story beyond being a German mercenary with Olympic-caliber throwing skills. Armed with a variety of trick javelins (similar to the trick arrows used by Green Arrow), Javelin had the ill-fortune to run into Green Lantern Hal Jordan in his first appearance, after he tried to steal an experimental jet from Jordan's employer, Ferris Aircraft. Javelin would later join the Suicide Squad, where he would be killed off on three separate occasions - possibly because nobody cared enough about the character to keep track of if he was alive or dead. Surprisingly, given his ancient weaponry gimmick, no story ever featured Javelin going up against Green Arrow until now.
That Hashtag Show reported on Javelin's upcoming appearance on Arrow. The role of Javelin has yet to be cast, though the producers are seeking a French-speaking male in his 30s to take on what is described as a “large principle role.”
The Arrowverse version of Javelin will have a more extensive background than his comic book counterpart, as well as a proper name - Leonard Gibbons. Presumably the name is a tribute to writer Len Wein and artist Dave Gibbons, who co-created the character of Javelin together. The character synopsis from the producers describes Gibbons as a French chemical weapons trader. The story synopsis for Javelin's first appearance also notes that he will have an encounter with Curtis "Mister Terrific" Holt, while Holt is working undercover.
Given Holt's Arrow background as an athlete who won the Bronze Medal for the decathlon at the 2008 Olympics, it's speculated that the two characters being specifically described as meeting in this manner is not a coincidence. It seems highly likely that Javelin and Mister Terrific have a history together, and that Javelin may have been introduced into the series specifically to serve as an arch-enemy for Mister Terrific, in much the same way that Black Siren was established as an arch-enemy for Dinah Drake's Black Canary. Even if there's no shared past between the two characters, pitting the two athletic technical geniuses against each other should prove interesting.
Source: That Hashtag Show