Shortly after the Galactic Empire began transitioning to TIE Starfighters as their primary fighters Darth Trepid, buried deep in the unknown regions, got the plans for them. After a couple years he upgraded the fighters using the advanced Rakataan, Kwa, and Gree technology he had discovered and other technology that his scientists developed.
This fighter is the TIE Quake, his bomber. It shares many similarities to the TIE Dread, but has a small bomb bay instead of a rear facing turret. This bomb bay can either drop the bombs in a gravity well, or when in space where dropping would do little, a mine layer. It has less speed and maneuverability than a TIE Dread, trading in favor of greater shielding and armor, similar to a Y-Wing, though a little more advanced.
Fighters in formation with the TIE Quake.
Chasing an Eta-5 that spotted them, the Dread pulls ahead, the Quake not fast enough to catch the interceptor.