Candlewick is introduced in chapter 30 of the novel. His real name is Romeo, though he is given his nickname on account of his slender, polished build. He is described as the most unruly of Pinocchio’s class, though he is the puppet’s best friend. He refuses Pinocchio’s invitation to a party celebrating his upcoming transformation into a real boy, and persuades the puppet to instead come with him to the Land of Toys (Paese dei Balocchi), where education and study are nonexistent. The two are transported to the Land by the Coachman, and spend their days indulging in play and idleness. After five months, both of them awake with donkey ears, which they conceal with tall caps. The two are reluctant to admit their condition to each other, but after some coaxing, they simultaneously remove their caps and laugh at each other. Their laughter soon turns to animal brayings and the two transform into a pair of donkeys. While Pinocchio is sold to a circus ringleader, Candlewick is sold to a farmer who makes him work at a water mill.
Pinocchio and Candlewick meet again in chapter 36, where it is revealed that Candlewick is dying from exhaustion. Pinocchio, now returned to normal, temporarily takes on Candlewick's job, and is laughed at when he reveals to Candlewick's owner that he went to school with the animal.
The Disney version of the character is not particularly different. Pinocchio meets Lampwick while riding towards Pleasure Island, where rowdy boys can play, smoke, drink, eat, fight, and destroy things. During their stay, Pinocchio and Lampwick become best friends and we find them in a pool hall drinking and smoking. Jiminy Cricket tries to convince Pinocchio to abandon the negative influence of Pleasure Island, but is shut down by Lampwick, who does not believe in following his own conscience as Pinocchio, when not subject to temptation, tries to do.
A short time later, Lampwick falls victim to the island's sinister influence and begins to transform into a donkey like all of the other boys. He grows donkey ears, a tail, and a muzzle. He remains oblivious to his fate until he begins braying. When he sees his face, he panics and begs Pinocchio for help. After he grows hooves, he begs for his mother and then falls to all fours. Braying uncontrollably, Lampwick proceeds to do damage to the pool hall with his hind legs and flees the area. Unlike the book, the film does not show what becomes of him, although one assumes that he is sold by the evil Coachman. Pinocchio escapes his friend's fate by leaving the island with Jiminy.