The Big Core Duo is the first and fourth boss of Gradius Rebirth. It is a modified Big Core.


Same old attacks, but this core transforms into a six-firing laser havoc. 

Attacks Patterns


At first, the boss will be a normal Big Core. However, after defeat, it will change into a different form. This form will first attack by firing a spread of six lasers at you a total of four times, before firing a pair of powerful lasers. It will then repeat the process.


In the updated version of the game, the music will change to an arrangement of the Nemesis 3 boss theme for the second form.

See also

Gradius ReBirth
Characters James Burton (Vic Viper) • GaudieVenom
Stages Stage 1Stage 2Stage 3Stage 4Stage 5
Bosses VolcanoIron MaidenBig Core DuoZub RushCrawler XMoai OrbSkeleton WaveEnigmaElectronic Cage MK2Xaerous Brain
Core Warships
Big Cores Big Core MK IBig Core Rev. 1.2Big Core MK IIBig Core MK II KaiBig Core MK IIIBig Core MK IV
Big Core variants BeaconBlaster Cannon CoreBubble CoreCircle CoreCoreshipCrater CoreCrystal CoreDellinger CoreDesert CoreHeaven's GateJuggler CoreLizard CoreNeo Big CorePerla MeraldaRexion CoreRolling CoreRotating LauncherShining CoreSuper Big CoreTerra CoreTriple Core (Life Force)Vanishing CoreViva CoreGenocide Core
Core-style bosses Abandon WarshipBubble EyeCovered CoreCovered Core MK IIDead EndKrakenMayhem WarshipMetal SlaveMisfit WarshipQueensrÿcheRiot WarshipPlate Core
Pseudo-Cores Death (Gau) • Death MK II (DeathDouble) • Death MK IIIBeta CoreNobilTriple Core
Tetran variants Tetran (Zylom) • Covered TetranCrystal Core D-X02Laser TetranTenny Rop