The VFB-9 Beta Fighter is based on the AB-01 Tread Armo-Bomber from the anime series Genesis Climber Mospeada. It is a large aerospacecraft capable of making orbit on the brute-force power of its three huge rocket engines. The VBF-9 is rather unaerodynamic, flying on the "brick with giant engines" principle. Its huge size and slender wings give it an extremely high wing loading, degrading its performance further - in terms of combat use, the Beta is a giant missile truck and little more in fighter configuration. In Battloid mode, the Beta is a hulking, powerful combatant with an impressive array of weapons including three heavy beam guns in each forearm and several missile launchers. The Beta's third configuration is a VTOL and walking configuration.
The Beta has the unique ability to dock with an Alpha Fighter (the AFC-01 Legioss Armo-Fighter in Mospeada), combining the two into a larger combat unit. The Beta fighter provides additional fuel for a docked Alpha and gives it the necessary thrust for reaching orbit. Beta Fighters were used as unmanned boosters for their smaller Alpha brethren.
In older references that are not considered secondary continuity, the VFB-9 was referred to as the "VBF-1" Beta Fighter.
The Beta was preceded in service by the SFA-5 Conbat, of which very little is known. This fighter, originally called AF-03 Convert in Mospeada, is the Armo-Fighter predecessor of the Legioss that was used in an earlier campaign (along with the AS-C03 Condor), and it could transform into Armo-Soldier mode.