New Star Wars Rebels concept art hints that we already saw the Original Trilogy fate of fan favorite character Captain Rex.

The current animated series story of Star Wars Rebels, stemming back to Star Wars: The Clone Wars, has always tangentially showcased the arc of one its most popular supporting characters in Captain Rex. Introduced in The Clone Wars as an elite Clone Trooper leading Anakin Skywalker’s 501st Legion, he became the conscience of the series; an idea that grew later in Rebels when a liberated, older, white-bearded version of the character emerged as a hero in the Rebellion against the Empire. However, it appears that Rebels may soon cleverly assign Rex an intriguing fate later in the timeline in the Original Trilogy films!

During a Star Wars Celebration panel on Thursday titled, Dave Filoni: Animated Origins and Unexpected Facts, the eponymous executive producer of Star Wars Rebels unveiled potentially poignant concept art for the upcoming Season 4 showing Captain Rex wearing a very familiar camouflaged uniform (modified with Clone gear,) resembling what Rebel commandoes wore on the Ewok-inhabited planet Endor in 1983's Return of the Jedi during the ground mission with Han Solo to deactivate the shield generator of the Second Death Star.
The image seemingly affirms a fan theory about the identity of one member of the mission, an older man sporting a similar bushy white beard – irreverently given the Christmas-inspired nickname "Nik Sant" or “Gramps” – who, in retrospect, could pass for Rex. While Filoni stopped short of outright confirming the idea that Rex will be retconned to be this member of the Endor strike team, he did stir the pot, stating in a cheeky manner when the concept art was shown:
“What’s that? That’s some kind of... don’t pay any attention to that. That shouldn’t even be in this folder! Why would he need camouflage? Doesn’t make any sense!”
Also present in the panel, Lucasfilm story group executive Pablo Hidalgo piled on the teasing, stating, “Just speculate away, we’re putting it out there.”
The idea that Rex might turn out to be the “Nik Sant” character is not new and has been posed to the creative personnel in the past. However, in presenting some rather strong evidence indicating this to be the case, Filoni and company not only elevate the hype for this fall’s Star Wars Rebels Season 4 in a new, unexpected aspect, but could also cement the canonical place of their character creation in a way that eagle-eyed fans who have long-noticed the bearded Rebel will enjoy, further elevating the animated series’ canon-adherent movie implications.
Of course, we probably won’t get confirmation on this idea until Star Wars Rebels Season 4 premieres on Disney XD this fall.