The two children, lost in the woods, stumble upon a dwarf village. They become friends with dwarves before they are manipulated and kidnapped by an evil witch. They're lured into her candy house, with cruel intentions, but are saved by the dwarves, along with some other children, and the witch meets her end.
Hansel and Gretel appear in Once Upon a Time, portrayed by Quinn Lord and Karley Scott Collins, as inhabitants of Fairytale Land. When their father went missing, the siblings sought out to look for him and ran into the Evil Queen who offered to help if they help her. The Queen asked them to enter the home of the Blind Witch and steal a bag while the witch is asleep. When Gretel asks why she doesn't go herself, the Queen claims that the house has a spell that keeps out adults but not children. She also warns them not to eat anything.
The children manage to sneak in the witch's house but Hansel eats a cupcake, awakening the witch. But they are able to get out of the gingerbread house alive and deliver the bag to the Evil Queen, which had contained the Poisoned Apple. She offered to let them stay with her, but Hansel and Gretel declined and tell her to find their father instead. The Queen became angry and sent them back to a forest, and it is revealed that the Queen was the one who kidnapped their father. When the Woodcutter informs her that his children refused to stay with her because "family always stays together", the Queen tells him that they can be together if they can find each other, forcing the Woodcutter to search for the children as well.
In Storybrooke, they are Nicholas and Ava Zimmer, the 12-year old twins of Michael Tillman, the auto shop owner. Their mother Dory passed away and have been living on their own ever since. They are first seen shoplifting for food and frame Henry Mills for it. Emma Swan investigates what happened, and goes on to interrogate the twins. When she learns they are orphans, Emma sympathizes with them since she also has no parents. She goes on to look for them using a compass Dory used to keep and goes to Mr. Gold to ask him if someone had purchased the item before.
Mr. Gold gives her the name of the man, Michael Tillman. He denies the children are his, but recognizes the compass. He wants nothing to do with them especially since he was unaware of their existence until now, and cannot accept the responsibility. If Ava and Nicholas' father continued to reject them, they would be taken to Boston to be placed into separate children's homes. Emma calls Michael to fix her car before they leave. Ava notices that her compass needle is moving. Tillman arrives in his tow truck and realizes that the children are his. He hesitates but then agrees to be their father, and then goes to his children.
Hansel first appears in "Pretty in Blue", while his sister Gretel first appears in "Sisterhood". Hansel in portrayed by Nathan Parsons as an adult and Seth Isaac Johnson, while Gretel is portrayed by Sara Canning as an adult and co-star Lily van der Griend. Living with his sister in the Land of Oz, Hansel and Gretel cross paths with the Witch in a gingerbread house who wishes to cook them. They narrowly escape and tell their father Ivo, about the Zelena, the Wicked Witch of the West, who left them for dead. Hansel tried to retaliate against Zelena only for her to burn parts of his arms.
The experience leaves Gretel thinking about her future and ways to protect herself. While Gretel learns candy-based magic, Hansel eventually leaves her to travel the realms, under the name Jack. When Henry arrives in the Magical Forest, he makes friends with Jack and bonded. After fighting off giants, Jack makes plans to head over to Agrabah as Henry decides to leave for Storybrooke. Sometime later, Jack makes his way to a resistance camp lead by Princess Tiana and reunites with Henry and is introduced to Cinderella.
Gretel learns about the Coven of the Eight and wishes to join them. Along with other witches, Gretel competes in a test to find a golden flower to win a spot in the coven. Gretel and Drizella decide to accompany each other during the test. However, while they are separated, Gothel goes to both of them saying that there are no golden flowers and that the test requires one to kill the other. Gretel attacks Drizella and as the two fight, Drizella fatally stabs Gretel in the back enabling Drizella to pass the initiation. Hansel continues to harbour a hatred for witches, especially after learning of Gretel's death during the initiation, vowing revenge on the coven members.
Years later, Hansel attempts to help the heroes to prevent Drizella's curse from happening, but fails to do so and is sent to the Land Without Magic after the curse is cast.
In Hyperion Heights, he is known as Nick Branson, a man believed to be Lucy's father. He is sought by Jacinda when child services takes Lucy away after Victoria Belfrey is arrested for the kidnapping of Eloise Gardener. As a lawyer, Nick takes on the case and wins it, reuniting Jacinda with Lucy. After regaining her memories thanks to Mr. Samdi, Nick later goes on a witch hunt, hunting down witches from the Coven of the Eight, cursed in Hyperion Heights. He kills Dr. Sage with poison and tries to kill Hilda with carbon monoxide in her bakery. However, Hilda survives and is brought to the hospital where Nick stabs her to death. He later goes after Ivy in a parking lot, but she fights him off and escapes. When Henry, who was reconsidering staying in Seattle rather than leaving for a new job, discovers scars on Nick, Nick poisons Henry and takes him as prisoner, vowing to continue his witch hunt and to make Henry aware of his true identity, only to be killed by Mr. Samdi. His dead body is later found by Rogers and Weaver.