The Teragun is energy based weapon which was created with Teraport technology. The weapon is like a disruptor, which nature of breaks down matter when it makes contact. When in use, the weapon appears to look like a gigantic flamethrower. However, it's visual effects is not seen with naked eye and requires special sensors to see the disruption in space-time.
Teragun was originally designed to combat the Pa'anuri, which are gigantic Dark Matter creatures who vulnerable to the nature of the Teraport.
The weapon first created by the Plenipotent Dominion with assistance with by Ellen Foxworthy with assistance her husband, Teraporter re-inventor, Kevyn Foxworthy. The weapons first saw use against the Pa'anuri in the Xuvoth star system, when a Pa'anuri Warship assaulted the system in bid to destroy the Unioc's homeworld of Othlin.
During the battle, the weapon was rapidly prototyped from the unstable Mark 3 to more stable Mark 4.
Later version of the weapon, the Mark 5, was retrofitted onboard the Tagon's Tough Cruiser, Cynthetic Certainty on it's mission to the Andromeda Galaxy to try distrupt Pa'anuri's efforts use Long Guns destroy Milky Way Galaxy locations remotely.