Thousands of disgruntled movie fans have signed a petition saying Ben Affleck does not have the "acting skill" or intimidation factor to play Batman.
Despite being hailed as an "extraordinary actor" by studio bosses, many fans have reacted angrily to the casting.
The actor was revealed as the Caped Crusader earlier this week and will star alongside Henry Cavill in the next Man Of Steel movie.
But more than 51,000 people have signed the petition stating "his acting skill is not even close to being believable as Bruce Wayne".
"He won't do the role justice," the petition says.
"He's not built, nor is he intimidating enough for the role of Batman.
"His portrayal of Daredevil was atrocious and he's not remotely close to an action star. Please find someone else."
The creator of the Change.org petition, John Roden, said he respected Affleck's work but felt he was "inappropriate for the role".
Oscar-winner Affleck, 41, was enthusiastically unveiled by film bosses who promised he would bring a "new dimension to the duality of this character".
"We needed an extraordinary actor to take on one of DC Comics' most enduringly popular super heroes, and Ben Affleck certainly fits that bill, and then some," said Greg Silverman, president of creative development at Warner Bros Pictures.
Christian Bale is understood to have turned down a big money offer to play Batman for a fourth time.
The English actor was praised by fans and critics for his brooding portrayal.
"He will burn Bale's legacy down to the ground," warns one person who signed the petition.
Another comment reads: "Affleck may (be) awash with many fine qualities, those which embody Bruce Wayne/Batman are not among them."
"Ben Affleck is a metro male with the strength of a wet noodle," one commenter adds.
The sequel to Superman reboot Man Of Steel - due out in 2015 - will see the two superheroes facing off against each other, according to director Zack Snyder.
Other actors to have played Batman on the big screen include George Clooney, Val Kilmer and Michael Keaton.
