Much of Bunnie's early life is unknown. As a child, she was found in the Royal Hills Zone by Rosie Woodchuck and Uncle Chuck, with no indication of where the young rabbit had come from.[3] She was taken to the city of Mobotropolis where she was raised under Rosie's care, until the city was taken over by Dr. Eggman. It was during this attack that Bunnie sustained some severe injuries. She was taken to Knothole Village and in order to save her life from these injuries, she was forced to have half of her body replaced with cybernetic limbs by Chuck.

Learning how to walk with her new robotic limbs was not only painful, but embarrassing which would lead to her and being picked on by other children, who purposely pronounced her last name as "Rab-BOT".[3] Her spirits were lifted when Miles "Tails" Prower, another child under Rosie's care, reassured her that he did not care that she has robotic parts, and that he saw her as a big sister. Some of her fellow refugees expressed similar feelings, and treated her as no different, inspiring Bunnie to make the most of this, striving to live her life to the fullest. Under Rosie's supervision, Bunnie tried with all her might to function properly with her cybernetics. Her bravery inspired Antoine D'Coolette to become braver, though Bunnie reassured him that it was not him "being brave" that made him brave, but him overcoming his fears were the reason he was brave.

A hedgehog by the name of Sonic came by the village, promising to defeat Dr. Eggman and save King Nigel Acorn. Though Bunnie and the others had their doubts, Sonic managed to pull through on South Island. This inspired her to join Sally Acorn, Tails, Rotor the Walrus and Antoine in forming the Freedom Fighters, fully abandoning her wheelchair.[7] As time passed, it became apparent that Bunnie's limbs needed an upgrade. She accepted, even though it would greatly decrease the chances of her ever getting her old limbs back. But Antoine reassured her that it wouldn't affect her courageous heart and beautiful