They think she has gone mad with the make-up box for the comedy with US star Tyler Perry.
The Irish Mammy is bizarrely caked in powder and sports bright red cheeks.
Some have compared her look to Aunt Sally in Worzel Gummidge or one of the stars of RuPaul’s Drag Race.
As our photos show, she is far more colourful than in her normal guise on BBC One show Mrs Brown’s Boys.
Brendan explained the reason behind Agnes’ appearance alongside Tyler, who dresses up as the elderly but tough Mabel “Madea” Earlene Simmons in the comedy.
He said: “It’s presumed that if you are going to go to America you either need plastic surgery or make-up.
“And of course, Agnes cannot afford plastic surgery.
“Madea also had a better wardrobe in the film. All Agnes had was a suitcase.”
The comedy actor revealed how – unlike the BBC – Netflix was not worried about how many “feckins” he could use in the film.
Brendan joked: “Feck no, we didn’t tell them when we were doing it.”
Brendan says he is already busy on projects for the rest of this year.
He revealed: “Right now I am working on a memoir – and I nearly have both pages of it done.
“And I am working on some Christmas specials.”
Recently, Brendan told people to “lighten up” after fans slammed him for making comments regarding Tyler’s “colour” on The One Show.
BBC viewers accused the star of making an “incredibly racist remark” towards the American actor and director.
Appearing alongside the Don’t Look Up star via video link the Mrs Brown’s Boys actor was asked whether he could see Tyler, 52, ever appearing on his award-winning comedy creation.
Replying to hosts Lauren Laverne and Harry Judd, Brendan gestured to his own face and said: “So far we haven’t had anyone of his colour in there so I don’t know if we could have him in.
“But you know what, I’d love that, but I think more importantly I’d love to do another movie with him.”
Speaking after the backlash, Brendan told the Sunday World that people should “lighten up”.
He added: “It’s very difficult to tell a gag without offending somebody.”
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