The Tyvarex, an EF76 Nebulon-B escort frigate, fought for the Rebel Alliance's navy during the Galactic Civil War. After the Battle of Hoth scattered the fleet, the Tyvarex joined the Fourth Division, which assembled at Rendezvous Point Delta-Three in the Mid Rim. Unfortunately, the Galactic Empire deciphered rebel codes, allowing them to monitor communications between the Fourth Division and another cell, leading to an attack on the Fourth Division. Commander Ellian Zahra's forces blockaded the Tyvarex against a star, preventing its escape and resulting in its destruction.
As an EF76 Nebulon-B escort frigate, the Tyvarex was outfitted with engines along with a deflector shielding system. This frigate also featured a life support system and several escape pods.
The Tyvarex served the Alliance Fleet of the Alliance to Restore the Republic in the Galactic Civil War against the Galactic Empire. Following the rebel retreat from the Battle of Hoth in 3 ABY, the fleet was divided into multiple groups to make it harder for the Empire to locate the entire Rebellion. The Tyvarex was assigned to the Fourth Division, which regrouped at Rendezvous Point Delta-Three near a star within the Mid Rim.
The Fourth Division then contacted another group, the Eighth Division, as part of the plan to gradually rebuild the fleet. However, Imperial Commander Ellian Zahra had created a signal analysis protocol that broke the rebel codes, enabling the Empire to locate any groups that communicated with each other. Zahra then initiated an attack on the Fourth Division's forces, using a wall of turbolaser fire to trap the starships against the star. The Tyvarex took significant damage, and its commanding officers requested starfighter cover while the crew evacuated. But, when the frigate's shields failed, Imperial TIE fighters attacked the Tyvarex, destroying it and killing the rebels on board.
The comic Star Wars (2020) 1, written by Charles Soule, with illustrations by Jesús Saiz, and published by Marvel Comics on January 1, 2020, featured the Tyvarex.