Trip Harlow was born as Deyna Sunesh on the planet Mirial in xx BBY. His father was a skilled hunter, and his mother a talented weaver, and they traveled as part of a nomadic caravan, following herds of migrating animals searching for food. As a child, he experienced troubling visions, oftentimes just before disaster stuck. His mother believed he was favored by the Force and wished to present him to the Jedi Order, but his father refused, unwilling to give up his only child. Instead, he began to teach Deyna how to hunt and track, passing along his knowledge of the land. Though his visions did not fully subside, he took his father's teachings to heart, and developed a strong affinity for the wilderness.

Years later while hunting with his father, Deyna experienced a vision of him in terrible danger, and awoke to find him gone. He took his rifle and pursued, eventually coming upon a rocky den, where his injured father was being circled by a great beast. He fired at the creature in a panic, but only angered it, causing it to lash out and strike him down. He braced for death, but it never came as his father leapt to his defense, shielding him and bringing the creature down, but taking a fatal wound. Try as he might, Deyna was unable to save him.

Deeply scarred by the loss of his father, Deyna withdrew into a shell of himself. His mother, torn by grief and worried for her child, decided it was time, and sent for the Jedi. His Force sensitivity was confirmed, and despite his age, he was taken to the temple to attempt training as an initiate. He struggled to learn even the basics of the Force, tormented by fear and guilt, and after only a year's time, he was turned away from the path. Ashamed of his failure and disillusioned with the Jedi, he fled the temple and hopped a freighter to the Outer Rim, determined to make something of himself on his own.

Taking on the name Trip Harlow, he spent his teenage years adrift, taking odd jobs and honing his skills as a marksman. He briefly joined a group of thieves, but ended up taking the fall for a heist and losing his arm in the process. As he approached adulthood and the galaxy fell into war, Harlow only grew more jaded. His visions worsened, haunting him with images of conflict that kept him from sleeping. Desperate to shut them out, he resorted to using deathsticks to numb his connection to the Force. He began to slide deeper into criminal work as a hired gun, the only jobs that paid well enough to fund his habit.