In U.C.0072, the Principality of Zeon begins development of a super-tank equipped with a nuclear fusion reactor and able to attack tactical targets such as armored fortresses or Big Tray-class land battleships. The Hildolfr was completed in U.C. 0077. Rather being called a Mobile Armor, it belongs to a category of its own, termed "Mobile Tank." As a tank, the YMT-05 Hildolfr is a mobile weapon designed for tactical artillery combat on Earth. Though having a relatively large and heavy frame, the tank is surprisingly fast and agile, and is equipped with a powerful 30 cm cannon that is capable of firing various projectile types with a maximum range of 32 kilometers. The power of the cannon is so great that the Hildolfr needs to be braced or else risk being knocked over by the sheer force of the shot's recoil. It is also equipped with multiple smoke dischargers.