He was once an oxygen salesman, but became a Rampartian Dissenter and named himself after Caliban, a character from The Tempest by William Shakespeare. Dissenters enjoyed outlawed works of mythology and fiction, and he became schooled in his Caliban character. He lived in the Dissenter haven of Alastor, a networked group of caverns.
In 2366, When he first spotted Deanna Troi in the caves, he mentioned the name Setebos, which referred to a character in a poem about the fictional Caliban written by Robert Browning. Caliban also quoted to her from The Tempest (Act 3, Scene 2). Although he was human, rather than half-human like the character, he was diminutive, had a mildewy odor, wore stained rags for clothes, and was covered with dirt.
Caliban broke Deanna’s handcuffs by smashing the chains with a pair of rocks. Later, when six Cephalic Security police officers and two one-eye robots broke into Alastor to arrest the Dissenters for illegal possession of fiction, he was seen riding one of the hovering one-eyes, blocking the robot’s eye with his hand and quoting Shakespeare. Caliban was killed during the assault, but most of the other Dissenters were able to escape.
Later, Deanna Troi had a waking dream in which Caliban and a band of Other-worlders assaulted CephCom, the headquarters of Cephalic Security in the city of Verity on the planet Rampart. Troi sensed either that the human Caliban still lived or had come back to life, and that he and the persona of the fictional Caliban were somehow united in the same body. (TNG novel: Gulliver's Fugitives)