BatArrow

BatArrow is the slash ship between Bruce Wayne and Oliver Queen from the DC Comics, DC Animated Universe and Young Justice fandoms.

Canon
Despite both Bruce and Oliver being DC heroes who come from a rich upbringing, as well them being two of the iconic Justice League members who don't have powers and have their own superhero family teams, the two of them aren't the best of friends. Even though they do work well together when it comes to saving people. That is why both Batman and Green Arrow have been featured in the same DC medias, that has them teaming up or simply cross paths with one another.

Return of the Dark Knight
After Oliver heard that Bruce was serving as Batman again while others want the Dark Knight to remain retired, the former Green Arrow decides to pay his old friend a visit. To show him that he supports Bruce's choice and wants to aid him. At first Bruce was against the idea, until he realised that he needs Oliver to assist him in his final battle with Superman. By having the one armed archer shoot an kryptonite arrow headed arrow at Clark. Despite the delay Oliver was able to do his part, before Bruce's time went out and got the world to believe that Bruce Wayne is dead. Oliver is one of the few people to know that Bruce is still alive and plans to ensure that the Batman legacy and mission is kept alive.

Fanon
Even though BatArrow isn't as popular as Superbat, the DC slash still has a decent amount of followers. With the two being DC heroes who don't have any powers, but are well skilled with the tools and fighting style they use to protect their home cities. As well as the two having a number of kids that they've adopted and made their prodigies. Making Batman and Green Arrow both similar, as well as different to one another. The two mostly differ in their general outlook on the world and personalities. Ollie being more upbeat, jokey and having a general more positive outlook on life, while Bruce is the pinnacle of dark brooding hero. Making them an appealing ship for many "Opposite's Attract" shippers.

Some fans of the comics have noticed that the Arrowverse gave Oliver Batman-like vibes. By putting on a play boy act and his hero persona in the series being much more darker than he is in the comics. As well as using a few Batman storylines as plotlines for the series. While this was a point of contention for many comic Green Arrow fans, this did add fuel to some shipping for him and Bruce. As with the later addition of Batwoman to the Arrowverse, meant that Bruce also existed and that they likely might know each other.

There is some shipping that comes from the DCAU and Young Justice fandoms. Although most seems to stem from the comics.

On AO3, there are currently 70+ written works.

Fandom

 * FAN FICTION

Trivia

 * Green Arrow is one of Batman's allies in the Injustice universe.