Born to traveling puppeteers and con artists Martin and Myrna, Jiminy Cricket is used by his unscrupulous parents to cheat and steal from people from a very early age, which they refer to as "helping". Though Jiminy wishes to be someone different, his parents chide that there is no changing who he is always going to be. As he grows older, Jiminy feels guilty for his actions, and always begs his parents to stop their thievery, though they never listen. One rainy night as he is setting up for his parents' puppeter show, a young boy under an umbrella approaches and shows great interest in puppets. The boy notices Jiminy is not happy and wonders why he doesn't just try something else. Jiminy responds the life he's in is inescapable. They share a kinship for listening to crickets chirp; something Jiminy likes doing which he hasn't done in a long time. He tells the boy to hurry home, and before leaving, Jiminy receives the umbrella to help cover him from the rain. Having enough of swindling people out of money, Jiminy visits a powerful dealer named Rumplestiltskin. After running an errand for him, Jiminy is rewarded with a thread of spun gold, but Rumplestiltskin can tell he wants something else. Jiminy explains his wish to be free of his parents so he can live his life, and is given a potion to get rid of them.
Later that evening, Jiminy's parents begin another one of their schemes. After a young couple offers them hospitality for the evening, his parents warn about an approaching plague. The couple forfeits many of their valuables to pay for the "cure" Jiminy's parents have. As they leave, he is fed up with his parents' actions and throws Rumplestiltskin's potion onto them, which has no effect. Jiminy realizes his parents switched the potion and gave it to the couple. He rushes into the home to see they have already been transformed into wooden puppets as the couple's young son, Geppetto, arrives home. Jiminy is horror-stricken to learn the boy is the same child he spoke to that day in the rain. Devastated by guilt, he desperately wishes on a blue star for his mistake to be undone. The Blue Fairy comes to his aid and, though she cannot reverse the damage, Jiminy wants to atone by living as a talking cricket and guiding the boy. She works her magic to turn him into just that as Jiminy assumes a new life as Geppetto's lifelong companion as he grows up. ("That Still Small Voice")
Many years later, the seven dwarves ask Jiminy for help because of Snow White's destructive turn in her life as she had become cold and cruel because of drinking Rumplestiltskin's forgetting potion. When he presents himself to Snow White, she expresses disgust at the sight of "vermin" and tries to swat him away. Though Jiminy tries to be the voice of reason, he indirectly gives her the idea to kill the Evil Queen. After Snow White ties Prince Charming to a tree so he doesn't get in the way of her mission, Jiminy loosens his bonds by chewing through the rope. In the nick of time, Prince Charming then stops Snow White's arrow from hitting the Queen and restores her to her old self with true love's kiss. ("Heart of Darkness")
Sometime during the war with the Evil Queen, Snow White toasts her allies in honor of her stepmother's birthday, whom she hopes will spend the rest of her birthdays never finding her. Within her castle, Regina sees this and begins crushing Snow White's heart. At once, Snow White stands up, seemingly feeling the pain of her beating heart being squeezed. The more pressure Regina puts on the heart, the more frantically Snow White unravels the knotting of her layered clothes, hoping to alleviate the pressure on her chest. When Snow White reaches the last layer and pulls on her shirt collar, Jiminy flies out from beneath the fabric and falls onto the table. The dwarves roar in laughter over this, before a tipsy Jiminy attempts to stand up, only to sway dizzily. From this, Regina realizes the heart she has is not Snow White's, and that someone switched it out. ("Souls of the Departed")
Following Snow White and Prince Charming's capture of the Evil Queen, which ends the war, the war council discusses what to do with her. Jiminy advises Snow White to consider killing the Evil Queen since she will never change from her dark ways. Snow White doesn't want to, but the other war council members agree the Evil Queen must be punished for her crimes, and sentence her to death. At the public execution, Jiminy watches the former Queen give her last, scathing words to everyone before being blindfolded as the Blue Fairy fires multiple arrows at him. Just before the arrows touch the Queen, Snow White calls the execution off. ("The Cricket Game")
Pinocchio, Geppetto's adoptive son, plays a trick on Jiminy by tying him inside a cuckoo clock, so that he pops out when the clock chimes on the hour. Pinocchio finds it humorous, but quickly shows remorse to the Blue Fairy since she told him before he can only stay human by being good. Instead, the Blue Fairy brings the news of the Dark Curse. She asks for Geppetto's help by telling him of an enchanted tree; like the one Pinocchio was fashioned from; which could save them. The Blue Fairy shows them the tree states it can save two people. Prince Charming and Snow White will be transferred to a land without magic in order to guide the savior. Geppetto worries and questions what will happen to Pinocchio since he was not always a real boy, but the Blue Fairy cannot answer his question because magic works differently in that land. He agrees to build the wardrobe only if he can save Pinocchio, which Jiminy questions. Instead, Geppetto angrily states that Jiminy can never repay his debt for what he did to his parents, but can start by staying out of his business. ("The Stranger")
At yet another council meeting, Jiminy suggests they should battle against the Evil Queen's curse, but this subject is dropped once the Blue Fairy parades in with the enchanted tree as Geppetto offers to carve a magic wardrobe out of it so Snow White, while still pregnant, can journey to another world and be unaffected by the curse. ("Pilot")
When the Dark Curse is enacted and quickly spreading throughout the land, the Blue Fairy comes to Geppetto again and tells him to forget their deal, and since Snow White is currently in early labor, both mother and daughter must go through the wardrobe together. She stresses the child must have a mentor in the new land, but Geppetto disregards what the Blue Fairy says, and makes preparations to send his son through the wardrobe first. As a farewell, Jiminy warns Pinocchio to watch out for temptation in this new world. ("The Stranger")