Transport 904 was a transport ship of the Galactic Empire. Circa 18 BBY, it was bound for the planet Wayland and the new facilities there when its cargo, a cloned Zillo Beast, broke loose and drastically damaged the ship. The crippled vessel dropped out of hyperspace and crash-landed on Silla. The information broker Ciddarin Scaleback caught wind of the vessel's state and sent Clone Force 99 to scavenge its cargo, unaware of what it was carrying.
Transport 904 was tasked with delivering a cloned Zillo Beast to an Imperial cloning facility on Mount Tantiss on the planet Wayland. The vessel's route was not charted into the ship's bridge due to the clandestine nature of the Imperial cloning program. It's hull had no discernable markings so it could not be identified to the organization.
Around 18 BBY, transport 904 was on route to the planet of Wayland when its cargo, a cloned juvenile Zillo Beast, broke free of its containment and attacked the vessel's crew. After it consumed almost all of the ship's crew and damaged it to the point of ripping it out of hyperspace, the Zillo Beast chased down a surviving Imperial clone commando through the ship's hallways. As the commando readied an electrostaff and prepared to stand his ground against the creature, the beast ambushed the commando and pulled him into the ceiling shafts screaming, where he was killed and consumed. The ship would eventually crash-land on Silla.
Not long after, the rogue clones of Clone Force 99 received word from their associate, information broker Ciddarin Scaleback, about the ship's crash and were sent to recover any valuable cargo it might carry. They found and boarded the ship, but after exploring it they soon came across the cloned Zillo Beast, who attacked them. The team managed to force the beast to retreat into a nearby forest by throwing a grenade at it, which blew a hole in the ship and allowed it to escape. As Hunter and Wrecker pursued the creature aboard the Marauder, Tech and Omega returned to the wreckage of transport 904 and attempted to extract information from its database. The two were eventually forced to flee as Imperial V-wing starfighters sent to respond to the crash destroyed the transport to prevent its purpose from being known.