The season finale of "The Flash" will not just be all about the definitive battle between the Scarlet Speedster and the man in the yellow suit. It is already known that Captain Cold will make a crafty return and that Oliver Queen and Firestorm will back up Barry in his fight against Eobard Thawne. 

As if that isn't electrifying enough, the final episode of the epic series' successful freshman run also serves as the fans' first ever look at some of the new superheroes to be featured in "Legends of Tomorrow," which is the much-awaited "Arrow" and "The Flash" spinoff. 

Ciara Renee, who has been cast as Hawkgirl in the upcoming series, revealed via Twitter that she and "some of [her] castmates" will be appearing in "The Flash." However, it is still unclear which of these cast members she was referring to. 

Seeing that Hawkgirl will debut on the show, media outlets surmise that Rip Hunter, who is played by Arthur Davill, will put in an appearance there, too. There's only a fat chance Caity Lotz or Franz Drameh will show up but it would be crazy and exciting to see either one in "The Flash" season finale. 

However, the likes of Heatwave (Dominic Purcell), Captain Cold (Wentworth Miller) or Dr. Martin Stein (Victor Garber), who all appeared in "The Flash," can easily show up there. Brandon Routh, who already flew to Central City once, can always return. 

All the same, it will be thrilling to see whichever heroes or villains would turn up with Hawkgirl in the season finale of the series. One thing is for sure though — the revelation sure had everyone at the edge of their seats. 

For now, fans better steel themselves for the long-awaited super-powered throwdown between Barry and the Reverse Flash in the season 1 ender of the "The Flash" titled "Fast Enough" set to air on May 19.