This was Steven Spielberg's last collaborative effort with Warner Bros. Animation until 2020 with the Animaniacs reboot series on Hulu.
Everyone involved with this show hated it. The theme song for the series included the lyrics: "Now Pinky and the Brain share a new domain. It's what the network wants, why bother to complain?", referring to the means of executive meddling. An image during the theme showed Pinky and the Brain getting kicked out of the Warner Brothers office during the song lyrics. In addition, a spoken line by the Brain towards the end of the theme states: "I deeply resent this."
Elmyra's last name, "Duff", is simply "Fudd" pronounced backwards.
Elmyra Duff, like her predecessor Elmer Fudd, is actually bald. Her hair is a wig.