The Concealer-class Prison Ship was employed by the Empire to transport Rebels and other criminal scum from location to location. This craft was in Imperial service at least a few weeks after the Battle of Yavin. Upon learning that a Rebel spy was operating within his command via the Imperial Security Bureau, Moff Lesan Ramier of the Brak Sector fed the spy information to set a trap for the Rebels. To facilitate his plan the Concealer-class Prison Ship Caged Animal was employed as bait. It operated under the ruse of transporting Rebel prisoners to an Imperial Garrison Base for interrogation, while in reality the Caged Animal was secretly carrying 40 Spacetroopers (with Mark I Armour).

    Moff Ramier intended to draw out the Rebels so that he could capture as many of them as possible so to gain vital intelligence against them. His plan managed to draw out a squadron of Rebel Y-Wings and a freighter - the Star Trader at the moon of Lish V. Although the Moff's plan to capture the Rebels failed it did allow for the destruction of six Y-Wings and the Star Trader. The ship's airlock for ship-to-ship transfers is only large enough to allow one person to pass through at a time.