The Horde Slave Transport was a gigantic vehicle used by the Evil Horde. Like most Horde vehicles, the front was decorated with the facial features of Hordak. It moved around on giant treads and had a special section on the front that served to load slaves into the transport.
Slaves were ordered to take place in a line on a walking escalator belt and take turns being turned into energy by the Slave Transport, then being sucked into its cargo hold.
On another occasion, Bow was captured at Green Thatch and loaded onto a Horde Slave Transport together with several other prisoners. They were to be taken to work at the energy mines in Dark Mountains.
She-Ra obstructed a Slave Transport's path through the Dark Mountains by dropping a large boulder in front of it. The two Horde Troopers who drove the transport were forced to stop use a laser to blast away the boulder. But by the time they had succeeded in doing this, She-Ra had climbed on top of the Transport and was tearing part of the roof off. The Troopers used a chute to exit the Transport, but were promptly imprisoned by the Princess of Power, using the scrap of metal she had just torn from the vehicle. After defeating Mantenna as well, She-Ra freed all of the prisoners.