Jiminy Cricket is the Disney version of the Talking Cricket, a fictional character created by Italian writer Carlo Collodi for his 1883 children's book The Adventures of Pinocchio, which Walt Disney adapted into the animated film Pinocchio in 1940. Originally an unnamed, minor character in Collodi's novel who is killed by Pinocchio before returning as a ghost, he was transformed for the Disney adaptation into a comical and wisecracking partner who accompanies Pinocchio on his adventures, having been appointed by the Blue Fairy (known in the book as the "Fairy with Turquoise Hair") to serve as Pinocchio's official conscience. In the film, he sings "When You Wish Upon a Star", the Walt Disney Company's signature song, and "Give a Little Whistle".
Jiminy Cricket's appearance bears little resemblance to that of actual crickets, which range from black to light brown and have long antennae and six legs; Jiminy Cricket has short antennae, a greenish-brown hue, and four limbs. Like most Disney characterizations, he is bipedal. He dresses in the manner of a 19th- or early 20th-century gentleman, characteristically wearing a blue top hat and a white dress shirt with an orange vest over a black jacket along with a yellow tie and khaki slacks with blue and yellow spats and carrying a burgundy umbrella and wears gloves similar to what Mickey Mouse wears. Since his debut in Pinocchio, he has become an iconic Disney character, making numerous other appearances, including in Fun and Fancy Free (1947) as the host and in Mickey's Christmas Carol (1983) as the Ghost of Christmas Past.
Source : Wikipedia