The Danza: Jessica Lange as Constance Langdon. Both "Langdon" and "Lange" are derived from the German word for "long", so its close enough
Dawson Casting: 24-year-old Evan Peters and 32-year old Bianca Lawson play high school students. Averted with Violet, played by 17-year-old Taissa Farmiga.
Enforced Method Acting: According to Ryan Murphy, Taissa Farmiga's reaction in the scene where her character Violet finds her own body was a genuine reaction, as Farmiga didn't see the prosthetic body until the scene was shot.
Brohst (bro-ghost) for Travis, Constance's boyfriend.
Frankenbaby, for the... creature in the basement from the first episode, AKA Nora's returned-from-the-dead child.
Tim Minear: He works as a consulting producer on the series. Hopefully, his curse won'taffect this show. (At four seasons...apparently it hasn't.)
Viral Marketing: Several videos, referred to as clues to the show's content, have been released on the show's Website and YouTube channel. These directly hint towards Vivien's miscarriage, her later pregnancy, and the rubber suit man's involvement, among other things. There was also a chance to sign up for a "house call" to come face-to-face with one of the show's characters.
What Could Have Been: Ryan Murphy confirmed on the audio commentary for the pilot that Constance's fourth child - about whom nothing but his/her (former) existence was ever revealed on the show - was originally intended to be an adult son who would have a significant recurring role in the season; in keeping with Constance's statement that there was something "wrong" with each of her children, he was to be an albino. However, the character was cut early in production for unknown reasons, as too was the "handsome albino" line Constance was meant to say as an in-jokey reference to him in the salon scene during the finale. Fanon seems to have adopted him, but in the official canon there's no indication of who the fourth child was, except for a line describing Adelaide as Constance's last surviving child that implies s/he is dead (though, considering the Our Ghosts are Different theme of the season, this could have been intended even if the character had made the cut).