DC Universe's 'Titans': Wonder Woman, Aquaman and three other unseen DC heroes the show may introduce in Season 3
There are five important DC heroes who are yet to make an appearance on the show even though their existence in the 'Titans' universe has been confirmed. Some of them have been directly referenced, others have only been implied to be around, but they're all major figures in the world of DC.
DC Universe's 'Titans' has introduced a number of great characters from across the world of DC Comics, including a number of more obscure characters. But there are five important DC heroes who are yet to make an appearance on the show even though their existence in the 'Titans' universe has been confirmed.
Diana of Themyscira's existence in 'Titans' was confirmed back in Season 1 with the introduction of Donna Troy / Wonder Girl (Conor Leslie). The Themysciran played a minor recurring role in Season 2 but with Donna's death and Rachel Roth / Raven (Teagan Croft) heading to their island paradise, there's a pretty good chance Wonder Woman might make an appearance at some point in Season 3.
We got confirmation that Roy Harper / Arsenal, also known as Speedy, exists in the 'Titans' universe early on in Season 2 when he gave information to Donna Troy and Kory Anders / Starfire (Anna Diop) about a rogue metahuman. His interactions with the heroes have so far only happened off-screen but he could make his debut on the show in Season 3, hopefully alongside the next entry on this list.
You can't have Roy Harper in the 'Titans' universe without bringing in his mentor, Oliver Queen / Green Arrow. Considering how popular the character is, the show will most certainly want to have a version of Oliver popping up at some point and with The CW's 'Arrow' coming to an end, it shouldn't be too difficult to arrange for a 'Titans' Green Arrow.
We know the Atlantean hero exists in 'Titans' because of his sidekick Aqualad / Garth (Drew Van Acker) making an appearance in Season 2. At the moment, we don't actually know if this is the half-human Arthur Curry Aquaman or the full-blooded Atlantean king version of the character we know from the 'Young Justice' animated series. So far 'Titans' does seem to be taking some cues from the animated show so our money's on the latter.
Fans have been waiting to see the Man of Steel on the show ever since his "son" Conner Kent / Superboy (Joshua Orpin) showed up in 'Titans' Season 2. At this point, it's actually quite surprising that he hasn't made an appearance considering all the very public trouble that Conner got himself into last season but hopefully, we'll get our appetite for Kryptonians satisfied come Season 3.
'Titans' Season 3 is expected to arrive on DC Universe in the Fall of 2020.