An anonymous user on Reddit, who claims to have been a visual effects artist on Justice League, has revealed that Desaad once played a role in the film.
The rumor is that Desaad was originally planned to show up in the movie in some capacity. In DC Comics, Desaad is a New God and one of Darkseid's followers from Apokolips - he was created by Jack Kirby and first appeared in Forever People #2 in May 1971. In the DC Extended Universe, Desaad would have look liked the Grim Reaper: a skull with a big cloak. This has not been confirmed by Zack Snyder or another figure responsible for the movie, so it's worth taking with a pinch of salt.
Desaad isn't the only character who was set to appear in Justice League earlier in the development process. It's also said that two more Green Lanterns were close to appearing in the movie: Kilowog and Tomar-Re, two senior members of the Green Lantern Corps. It's rumored that they were going to be appear in a post-credits scene, but they were replaced by Lex Luthor and Deathstroke coming together to form a league of their own.
Now in theaters, Justice League stars Ben Affleck as Batman, Gal Gadot as Wonder Woman, Henry Cavill as Superman, Amy Adams as Lois Lane, Jason Momoa as Aquaman, Ezra Miller as The Flash, Ray Fisher as Cyborg, Jeremy Irons as Alfred Pennyworth, Diane Lane as Martha Kent, Ciarán Hinds as Steppenwolf, Jesse Eisenberg as Lex Luthor and J.K. Simmons as Commissioner Gordon.