4) Solomon Grundy
Born on Monday and dead by Saturday, Solomon Grundy might be one of the more familiar characters on this list. Since his inception in 1944, Grundy – a Hulk-like zombie – has stuck around as a long-term enemy of Superman and Batman. He’s sort of also appeared in Arrow – though it was such a revisionist take on Grundy it was hardly him at all.
In the show, Cyrus Gold (Grundy’s living name) is injected with the drug Mirakuru and so gains super strength and agility. Gold stuck around for three episodes before being killed off, without ever becoming the character as we know him. Ideally, the character would come back from the dead in the future, to be properly reborn as Solomon Grundy.
Unfortunately, an issue here might be that Gotham is also introducing Grundy in season three. Given that, Arrow might have missed its chance to do the character justice. Let’s hope not, though.