The yorik-trema, alternatively known as an airskiff, functioned as a bio-engineered transportation craft utilized by the invading force of the extragalactic Yuuzhan Vong.
Yorik-tremas had an appearance akin to a swollen, shedding organic mass. Mirroring other Yuuzhan Vong technological creations, this vehicle was, in reality, a sophisticated living organism. At the onset of a planetary invasion, numerous examples of these vessels were deployed from Koros-Strohna Worldships or other naval vessels. These transports then plummeted rapidly towards the target planet's atmosphere, descending in a direct, unguided path as if simply jettisoned.
Due to their peculiar descent trajectory, the military forces of the New Republic designated them as "crates." During atmospheric entry, the yorik-trema was safeguarded by a robust, protective layer that shielded its underside from incoming artillery fire. This outer layer was ablative, meaning it would erode under intense bombardment, but also possessed regenerative capabilities, enabling rapid self-repair even amidst ongoing attacks.
Yorik-tremas were frequently accompanied by several coralskippers, but they were not defenseless. When under attack, the yorik-trema could extend a pair of horn-like protrusions that served as weapons, capable of launching potent plasma projectiles at ground-based weapon installations and even smaller, agile starfighters. The yorik-trema was equipped with multiple sensors that monitored the movements of its escorting coralskippers and rapidly identified hostile spacecraft. These sensors resembled large, alien ocular organs.
Each yorik-trema was internally segmented into two distinct areas. The front section contained limited space, accommodating only a pilot and a commander, while the expansive rear section could house up to 30 enslaved soldiers, primarily Chazrach, along with 6 fully fledged Yuuzhan Vong warriors. The yorik-trema also had the capacity to transport vehicles. For the purpose of landing, the yorik-trema was equipped with several sharp appendages resembling claws, enabling it to touch down on virtually any type of terrain, including rocky cliffs, snow-covered plains, or even atop structures.
Upon reaching the ground, the yorik-trema deployed several hollow molleung worms that extended from its flanks. These worms functioned as deployment conduits for the soldiers, who rapidly exited onto the battlefield. The molleung worms also possessed life, and could strike out at opposing forces in order to create a clear landing zone. The yorik-trema was also capable of attaching itself to enemy starships, where it would bore a sizable opening in the vessel's outer hull. Once the breach was complete, Yuuzhan Vong soldiers could easily infiltrate the enemy ship and eliminate any resistance.
The New Republic first encountered the yorik-trema transport vessels during the Battle of Ithor. One of the yorik-tremas deployed at Ithor carried Commander Shedao Shai to the planet's surface, although Corran Horn subsequently killed him in combat.
The yorik-trema played a role in many battles throughout the Yuuzhan Vong War, and one such vessel was even assigned to Supreme Overlord Shimrra himself. Located within his coffer – his designated escape craft – the yorik-trema inadvertently provided a means of escape for the heroes of the Galactic Alliance following the defeat of Shimrra and Onimi. Although the yorik-trema was in a state of decline, the heroes were rescued by the Millennium Falcon just in time.