The Missile Boat was an advanced Imperial starfighter designed by Admiral Thrawn and built by Cygnus Spaceworks. Designed as a countermeasure against the rogue Grand Admiral Demetrius Zaarin and his supply of TIE Defenders, the Missile Boat was a descendant of the Alpha-class Xg-1 Star Wing, also manufactured by Cygnus Spaceworks. The Missile Boat relied primarily on warheads for dogfighting and assaults, a notable difference from other Imperial starfighters, which relied more heavily on laser cannons. The Missile Boat also included an innovative propulsion feature known as the SubLight Acceleration Motor (SLAM).