Warning: The following contains possible spoilers for "Rogue One: A Star Wars Story."

We've known for a while now that Darth Vader may or may not show up in "Rogue One: A Star Wars Story," the first non-saga Anthology movie from Lucasfilm. But now comes word that another original trilogy "Star Wars" villain could make an appearance as well.

Jason Ward, Editor-in-Chief of Making Star Wars, reports that Grand Moff Tarkin could also make a cameo in the first "Star Wars" spinoff.

"Concept art for Rogue One reportedly does feature the Grandest of Moffs doing what he does best - being shrewd and in command," Ward wrote.

Peter Cushing, the actor who originally played the character, passed away in 1994. Whether or not Lucasfilm plans to recast him or borrow scenes from "A New Hope" should his role in the film be kept remains to be seen. It's important to remember, however, that these are still unconfirmed rumors. If true, though, here's how Ward says the film will handle the inclusions.

"Not only was it proposed that Darth Vader would be an attack dog on the battlefield messing up any Rebels that get in his way, but they also proposed he talk to Grand Moff Tarkin on a Star Destroyer Bridge."

Tarkin was a ruthless leader in the Galactic Empire; a man completely without remorse. In many ways, he was the political version of Vader. But until we see visual evidence or come across leaked script details, we can't say for sure whether or not he'll appear in "Rogue One."

"Rogue One" will take place in between "Episode III: Revenge of the Sith" and "Episode IV: A New Hope" on the "Star Wars" timeline and will follow a group of Rebel soldiers who steal the plans for the original Death Star. The movie has put together an impressive cast that includes Felicity Jones, Ben Mendelsohn, Donnie Yen, Mads Mikkelsen, Diego Luna, Alan Tudyk, Forest Whitaker and more. Directed by Gareth Edwards, "Rogue One: A Star Wars Story" will arrive on Dec. 16.