Who is the Disney character that serves as Pinocchio's conscience?

The Disney character who serves as Pinocchio's conscience is Jiminy Cricket.

In Disney's 1940 animated film Pinocchio, the Blue Fairy appoints Jiminy to guide the wooden puppet and help him distinguish right from wrong. Jiminy also narrates much of the story and accompanies Pinocchio through encounters with characters such as Honest John, Gideon, and the Coachman. His role is represented symbolically as Pinocchio's moral voice, even though Pinocchio repeatedly ignores his advice.

Jiminy Cricket was adapted from the Talking Cricket in Carlo Collodi's 1883 book The Adventures of Pinocchio. Collodi's cricket was a minor figure, but Disney transformed him into a central, witty companion. Animator Ward Kimball supervised the character's animation, and Jiminy became especially memorable through the songs “When You Wish Upon a Star” and “Give a Little Whistle.” Geppetto is Pinocchio's father, while Figaro and Cleo are other characters—not his conscience.