- "Dear me, my sweet Ecco.. there will never be one like you.. but I suppose there are other fish in the sea."
- —Jeremiah Valeska says to a dying Ecco
Ecco is a precursor to Harleen Quinzel alias Harley Quinn and was Jeremiah Valeska's assistant and proxy who devoted her life to him, first appeared in Gotham TV series. Even after Jeremiah's descent into insanity, she still remained loyal to him. She assisted him in his plans to destroy Gotham Cityand rebuild it in his image. During No Man’s Land, she formed the Church of Jeremiah Valeska to gather recruits to help him dig a tunnel into Wayne Manor, and helped him recreate the Wayne murders as well as prevent the reunification of Gotham with the mainland by releasing toxic chemicals into the air. After Jeremiah was rendered brain dead and imprisoned in Arkham, Ecco would work at Arkham as his nurse. Ten years later, they would escape Arkham and attack Barbara Kean, which would result in Ecco being stabbed by Barbara and then shot dead by Jeremiah due to the severity of her wound.
Behind the scenes
- She may also be based on or a reference to Alicia Hunt from the 1989 film Batman, who was a blonde mistress and accomplice to the Joker and later wore a porcelain mask due to a disfigurement upon her face, much like Ecco's Mummer mask.
- Her name may possibly be a homage to the character of Isabelle Cheranova aka Echo, who was a Russian assassin that fought Batman during the events of the No Man's Land comic crossover event, an event that served as partial basis for the last episode of Season 4 as well as the entirety of Season 5.
- Before killing her, Jeremiah says that Ecco is “no longer his echo”, implying her alias was chosen because of how devoted she was to Jeremiah, literally echoing his will.
- Echo was also an alias used by the Riddler's recurring henchwoman Nina Damfino, a member of the duo Query and Echo.
- Coincidentally, Francesca Root-Dodson has said that she initially auditioned for the role using a Russian accent.
- Ecco is a precursor to Harleen Quinzel alias Harley Quinn, a character created by Paul Dini andBruce Timm that was originally introduced in Batman: The Animated Series in 1992. Due to the popularity of her character, she was eventually adapted into the DC Comics. She is usally depicted as accomplice and lover of the Joker, whom she met while working as a psychiatrist at Arkham Asylum, where the Joker was her patient and consequently drove her insane. She also had her own strong solo career and was also a member of the Gotham City Sirens alongside Catwoman andPoison Ivy. Even though Ecco isn’t Harley Quinn, she still has some things in common with her, such as being a henchwoman to the show's version of the Joker as well as being in love with him, and donning a jester costume with a red and black diamond design, as well as later painting her face like a clown and dressing in fashions with red, black, and white. Where as Harley Quinn was portrayed as more goofy and misguided in her love for the Joker, Ecco was either stoic or outright sadistic and insane, echoing Jeremiah’s personality after he was driven insane by Jerome. Ecco was also more competent than Harley Quinn as she technically never failed any of the tasks Jeremiah gave her, and only died by his hands due a fatal wound she already suffered because of her carelessness.
- Even though her alter ego remains unnamed during her appearance in "A Dark Knight: That Old Corpse", her alias "Mummer" was revealed in the episode's end credits.
- Francesca Root-Dodson only auditioned for the episode "A Dark Knight: Mandatory Brunch Meeting" with a Russian accent, she didn’t know yet that she was going to reprise her role. In fact, she was supposed to appear in only one episode, then it was chosen to call her back.
- Francesca was called back to read the script of "Penguin, Our Hero" to make sure she was a good fit for playing Ecco after she shot herself, since the character in Season 4 was the opposite of what she's been in Season 5.
- Francesca has stated that she watched some clips of Suicide Squad and Batman: The Animated Series to have an idea of what Ecco's voice was supposed to sound like, she eventually chose to go for her own way about the character's voice pitch, and then the physical and facial movements.
- Ecco called Selina "Puddin", which is a reference to what Harley Quinn would always call the Joker. Likewise, Selina telling Ecco not to call her "Puddin" could be a reference to Batman: The Animated Series, when the Joker told Harley Quinn not to call him "Puddin".
- Harley Quinn was discussed to be used in the Season 3 finale "Heroes Rise: Heavydirtysoul", as someone connected to the Cult of Jerome. This never came about.
- At one point, the showrunners considered turning Barbara Kean into Harley Quinn.
- Harley Quinn is foreshadowed when Jeremiah says he “supposes that there are other fish in the sea”.
- Francesca revealed that Ecco adores and loves Jeremiah, as she thinks he is the bee's knees. She said that she thinks that their relationship is not really healthy.
- Francesca said that she got to keep Ecco's outfit from "A Dark Knight: Mandatory Brunch Meeting" when the filming of the series wrapped up.