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Big Core MK I

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Big Core MK I
Big Core
Appears In Gradius
Gradius II
Gradius III
Gradius V
Gradius Gaiden
Gradius ReBirth
Nemesis (MSX)
Nemesis 2
Nemesis 3
Solar Assault
Gradius NEO
Gradius NEO Imperial
Jikkyō Oshaberi Parodius

Otomedius Gorgeous
Otomedius Excellent
Cosmic Wars
Theme Music Aircraft Carrier (Gradius I, II, III, NEO, NEO Imperial and Jikkyō Oshaberi Parodius)
Last Evil (Gradius ReBirth)
Mazed Music (Otomedius Gorgeous)
Shower of Stars (Otomedius Excellent)
Dark Force (Gradius '93)


Big Core MK I is the famous staple boss in the Gradius series. They are usually found in a Gradius game in one form or another as an actual stage boss, in a boss run, or as regular enemies. (In Gradius V, they are very numerous in stage 3 at several parts and in stage 7 at the beginning of the stage.) In Gradius Gaiden, it is in the second stage as one of the boss debris. In Nemesis II (MSX) before boss 4, a fleet of them appear for you to destroy.

Other games have made several variants of the Big Core MK I that have it with extra armaments, different attack patterns, or transformations.

In Gradius NEO Imperial, Big Core MK I is the player's vessel instead of the Vic Viper. Here some additional weapons are available besides the traditional four laser shot.

Attack Patterns

Big Core MK I attacks by shooting four blue lasers at the player while moving up and down. They have only one core (the weakness for most bosses) which is protected by four panels. It is usually easy to destroy.

However in Jikkyou Oshaberi Parodius, it becomes a little harder to deal with. At first it will attack normally, but it will suddenly turn around and begin attacking you from behind. When it returns to the right side, it will move faster and shoot it's lasers haphazardly and non-sequentially.

In GR3, it has gained two extra lasers and has turned two of its lasers diagonal. The lasers it fires will bounce off walls. After taking enough damage, the core is attacked and merges with the Blind Guardian. Later, on stage 7, the first boss in the boss rush is two normal Big Cores at once, except they can drop glowing mines.

In Otomedius Excellent, the Old Big Core is found in the Great Waterfalls (Stage 4) where one of its laser cannons shoots down Meta Lium and her Big Core DX before the player arrives at the massive ship and it emerges from the water. Old Big Core is comprised of a three-core Gunwall situated at the back of the ship's barrier area with defenses on the line sections where the barriers used to be. The three leftmost barriers have guns on the top and bottom which will fire concussive lasers (if both are intact) and normal shots, while the vertically-moving gun turret on the last barrier will fire two rows of normal shots at the player. Sacrificing a hit on the force field in order to move past it and directly attack the three cores is highly recommended.


Big Core MK I appears only in Vol.1 of Salamander OVA when trio was attacked by Tentacle Golems. When it appeared, Gradius forces destroyed it.

Old Big Core

Old Big Core is a giant Big Core MK I that appears in Otomedius Excellent. It is not known if it has a pilot. One of its laser cannons on the front shoots down Meta Lium's Big Core DX before the player makes their approach. When the player reaches the laser cannon, it fires off to the side before Old Big Core moves and floats most of the way out of the water. To fight Old Big Core, the player heads inside the path left open because there are no solid barriers impeding forward progress. As it turns out, the inside of Old Big Core is a Gunwall situated in front of the actual, full-size core to the ship. There are two smaller mini-cores, one on either side of the central, not-so-mini core which is about as big as the player is tall (if not a little bigger). The top and bottom edges of the three leftmost barrier sections have turrets, and together will fire a concussive laser to restrict movement, then each fire a normal shot at the player. To prevent the concussive laser attack, take out either side of each pair. The main threat, however, is the moving turret on the final barrier section's rail that moves up and down with the player and fires two rows of normal shots. Sacrificing a hit on the force field to move past and get behind this moving turret gun is the best option for destroying the gunwall's three cores; destroying the weapon is not advised unless the player needs to do so in order to obtain a weapon card in a certain loop and difficulty.

Big Core Custom

As mentioned before, the Big Core in Gradius Neo Imperial plays the hero role instead of the Force Viper. Its mission is to escape from the Lars Empire, presumably with the intent to join the Gradius Union. Unfortunately, at the end of the game it meets a tragic end at the hands of the Force Viper's pilot, who did not understand it was escaping. With the power bar reading SBMLN?, the Big Core Custom is armed with additional weapon choices, a Speed Up option in the first slot and a Shield in the last slot.

  • BC Custom weapons
    Beam Shot - This is the Big Core's iconic four-shot laser weapon. It starts at two shots with little rapid fire.
  • Missile - This weapon shoots a stream of up to six medium-sized missiles across the screen. It starts at four missiles.
  • Laser - This weapon shoots a powerful red laser which is similar to the Force Viper's Wide Laser from Gradius Neo. It starts out small, but at full power is as large as the Big Core.
  • Area Napalm - This weapon sets up a 3 ✕ 3 grid that stays in position relative to the ship as you move. Pressing a button from 1 to 9 on your phone's number pad will bomb the corresponding grid square, and any target within that grid will be hit by a small spread blast. Powering up this weapon increases the number of napalm blasts.


Big Core Gallery
Big Core, as it appears in the X68000 port of Gradius.  
Garudius '95's Big Core
Big Core, as it appears in the NES port of Gradius.  
Big Core Nemesis ZX Spectrum.gif
Big Core, as it appears in the ZX Spectrum version of Nemesis.  
Big Core in Salamander.png
Big Core, as it appears in Salamander. It is fought 3 times.  
Big Core Gradius II.gif
Big Core, appears during the Boss Rush Stage in Gradius II. Image from NES port.  
Big Core Nemesis 3.png
Big Core, appears during the Boss Rush Stage in Nemesis 3.  
Big Core Jikkyō Oshaberi Parodius.gif
Big Core, appears during the Boss Rush Stage in Jikkyō Oshaberi Parodius.  
Big Core in Gradius V.jpg
As it appears in Gradius V. Note the guns on the sides of the ship. These are never used.  
Big Core MK I otomedius.png
Big Core, as it appears in Otomedius.  
Cameo Big Core in Force Gear.png
Big Core's cameo in Tokimeki Memorial's hidden easter egg game, Force Gear.  
Big Core Garudius '95.gif
Big Core, as it appears in the fangame Garudius '95.  
Big Core Shoot The Core.gif
Big Core, as it appears in the fangame, Shoot The Core.  
Big Core in GR3.png
Big Core, as it appears in the fangame, GR3.  
Big Core unused in Otomedius Gorgeous.jpg
Big Cores unused in Otomedius G.  
Big Core Gradius ReBirth.png
Big Cores in Gradius Rebirth.  
Big Core in Yu Gi Oh!.jpg
Big Core, as it appears in Yu-Gi-Oh!.  
Big Core Anime.jpg
Big Core, as it appears in the Salamander anime.  
Old Big Core.png
"Old Big Core", a boss in Otomedius Excellent!.  
Old Big Core.png
"Old Big Core", a boss in Otomedius Excellent!.  
Big Core Gradius Phone.png
Exclusive Big Core Bosses in Gradius Mobile Phone.  
Ally BC MK1 appear.png
A friendly Big Core appears by the Vic Viper in GRADIUS 2012's video. 
BC MK1 details.png
An up-close look at the ally Big Core seen in GRADIUS 2012's video. 


  • Big Core MK I is also a Yu-Gi-Oh! card and appeared in Yu-Gi-Oh! GX Episode 71.
  • It was also a boss form in Rocket Knight Adventures.
  • It also guest stars in a mini game in Blades of Steel.
  • In Otomedius Excellent, if Tita Nium is used by the player, then she comments that Old Big Core's code is incompatible (to her BC-SYSTEM, it would seem) when she enters the barrier section of the ship to fight the gunwall.
  • Big Core MK I also appears in the flash game Hyper Exelympic, based on Triggerheart Exelica.
  • The background video for GRADIUS 2012 in beatmania IIDX 20 tricoro sees the Vic Viper joined by a friendly Big Core MK I.

Gradius Bosses
Sub Bosses VolcanoZub RushMother and ChildIron MaidenTentacle GolemElectronic Cage

Skeleton Wave (PC Engine) • Three Core Crystals (MSX) • Polliwog Rush (Spectrum)

Bosses Big CoreCell NucleusBrain
Core Warships
Big Cores Big Core MK IBig Core Rev. 1.2Big Core MK IIBig Core MK IIIBig Core MK IV
Big Core variants BeaconBlaster Cannon CoreBubble CoreCircle CoreCoreshipCrater CoreCrystal CoreDellinger CoreDesert CoreHeaven's GateJuggler CoreLizard CoreMaster CoreNeo Big CorePerla MeraldaRexion CoreRolling CoreShining 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 CoreScrap Wall
Pseudo-Cores Death (Gau) • Death MK II (DeathDouble) • Death MK IIIBeta CoreGraveTriple Core
Tetran variants TetranCovered TetranCrystal Core D-X02Laser TetranTenny Rop

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