The Big Core Duo is a boss in Gradius ReBirth.


The Big Core Duo is the first and fourth boss in the game. It is a specially-modified Big Core. This Big Core starts with the same old Quad Shot attack, but then it transforms into a six-shot-firing and laser-sweeping havoc of a Core warship.

Attack patterns


At first, the boss will be a normal Big Core and attack as it always has. However, after its defeat, it will take off to the background, and change into a different form by flipping over and opening its sides. 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, continuous lasers that will sweep the screen with its movement. From here, it will repeat the process until it is defeated.


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

See also

Gradius ReBirth
Characters James Burton (Vic Viper) • GaudieVenom
Stages VolcanoCellMoaiWastelandAntichthon
Bosses VolcanoIron MaidenBig Core DuoZub RushCrawler XMoai OrbRe-BoneEnigmaElectronic Cage MK2Xaerous Brain
Core Warships
Big Cores Big Core MK IBig Core MK-I Rev.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 CoreLaser CoreLizard CoreNeo Big CorePerla MeraldaRexion CoreRolling CoreShining CoreSuper Big CoreTerra CoreVanishing CoreGenocide CoreOdin Core
Core-style bosses Abaddon WarshipCovered CoreCovered Core MK IIDead EndKrakenMayhem WarshipMetal SlaveMisfit WarshipQueensrÿcheRiot WarshipPlate Core
Pseudo-Cores DeathDeath MK II (DeathDouble) • Death MK IIIBeta CoreNobilTriple CoreCrash Bam
Tetran variants Tetran (Zylom) • Covered TetranCrystal Core D-X02Laser TetranTenny Rop
Parody Cores Candy CoreDecoration CoreDecoration Core MK IIViva Core
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