*Ellen Yin is a GCPD detective for Gotham City Police Department. Initially working with Ethan Bennett to capture the Batman, she eventually allied with the Dark Knight after Bennett's transformation into Clayface. Yin was created specifically for the animated series The Batman, though it has been speculated that she was an adaptation of Ellen Yindel.

In the episode "Fire and Ice" she is seen wearing a red sleeveless dress to the police charity ball. She is also seen wearing a black winter fur coat, with a red turtle-neck sweater earlier in the episode. In the episode "Strange Minds" Yin is forced to wear a red and purple jester costume after being kidnapped by the Joker. In the episode "Traction" Yin is temporarily hospitalized by Bane and is seen wearing a hospital robe, with several bandages on her face.

In the episode "Riddled" Yin briefly wears a bomb suit as she tries to disarm a bomb set by the Riddler. In the episode "Topsy Turvy" Yin is sealed in a playing card by the Joker. The card design has a purple royal robe with two white hands, each holding scepters and one of them is upside down. The card also features a crown above Yin's head, which conceals her ponytail and the bottom half of the card has a face of a woman with long dark hair. The Joker calls Yin "Queen of Spades".

Yin quickly grows fond of her partner after being tasked with unmasking the Batman. Having shown to be an effective detective, she gains the approval of Chief Angel Rojas. She had a difficult relationship with the Batman initially, and not warming to his alter ego Bruce Wayne so easily either. Ellen doesn't have it out personally for The Batman. As a vigilante, he's breaking the law, and as Bruce Wayne she only sees a spoiled billionaire playboy, despising his seemingly silver-spoon arrogance. She also thinks Catwoman is similar to Batman. She tried to take down Joker, Penguin and Mr. Freeze, but Batman always beat her to the punch.

When her partner and friend Ethan Bennett is transformed into Clayface, due to Jokers putty. Yin loses one of her best friends in the city. Before she and Batman parted ways after fighting Clayface, Batman handed her a Batwave commlink, telling her to call him whenever she needed. Keeping the commlink, Yin later calls Batman her new "partner" during a coffee shop meeting with Ethan's best friend, Bruce Wayne. Yin soon decides to test her new partnership with Batman, asking for his help in "The Cat, the Bat and the Very Ugly" as she investigates Catwoman and her mysterious new partner in crime. When Yin discovers that the mysterious partner is none other than the Batman himself, she questions her trust in the caped crusader. She decides to trust him though, after he and Catwoman stop one of Penguin's schemes to hold all of Gotham at ransom.*