We previously put it forth that John Cleese's character might be connected to Alfred in that they both were a part of the British military. We might not be too far off as Twitter detectives are saying John Cleese could be playing Wintergreen. In the comics, Wintergreen is former member of the British Army and aide to Deathstroke. The two became good friends when Wintergreen was working for MI-5 and the British Army.
Deathstoke has already been teased for Justice League, and Joe Manganiello will be playing Deathstroke in the Ben Affleck Batman movie, so Wintergreen does fit.
"Justice League" has a November 17, 2017 release directed by Zack Snyder starring Ben Affleck as Batman, Henry Cavill as Superman, Gal Gadot as Wonder Woman, Jason Momoa as Aquaman, Ezra Miller as The Flash, Ray Fisher as Cyborg, J.K. Simmons as Commissioner Gordon and Willem Dafoe an Atlantean, Nuidis Vulko.
Synopis:
Fueled by his restored faith in humanity and inspired by Superman’s selfless act, Bruce Wayne enlists the help of his newfound ally, Diana Prince, to face an even greater enemy. Together, Batman and Wonder Woman work quickly to find and recruit a team of metahumans to stand against this newly awakened threat. But despite the formation of this unprecedented league of heroes—Batman, Wonder Woman, Aquaman, Cyborg and The Flash—it may already be too late to save the planet from an assault of catastrophic proportions.