"Brennan stayed in character, even when the cameras were not rolling on My Darling Clementine. "Don't whip me, Pappy, please!" the actors pleaded. John Ireland, who appears as one of Clanton's sons, said that off-screen Brennan was like the character he played. Walter Brennan, on-screen and off, almost always knew his own mind, an attribute that sometimes resulted in an inability to appreciate other points of view. He simply shut them out, like the single-minded Ike Clanton."