Zelos Force (Spelled 'Zeros Force' in Japan) is a boss that occasionally appears in the Gradius series. It first appeared in Salamander as the core of the planetoid, Salamander. It always appears as a giant red eyeball and was also created by the Bacterians as a planet-modifying system to change planet Latis into an organic fortress for the Bacterians. Since it is a organic weapon and also a living creature, some Zelos Forces are seen in different situations they normally would be in - such as manipulating a core unit, transforming into another creature, and living in wild.

Attack Patterns

Whilst originally appearing as a non-combatant final boss. In a few games, Zelos gained additional attacks:

  • Salamander: Zelos' only method of harming the player in this game is to collide with them, as he approaches from behind, it may surprise new players. He will then be held in place by the four stabilizers, these must be destroyed to eliminate Zelos. Upon his defeat, the screen will lurch forward quickly, and the base will attempt to shut the player in - this is very hard to survive.
  • PC Engine port of Salamander: In this game, Zelos not only approaches from behind but he also shoots red lightning and his core has to be hit in order for him to be destroyed.Lightning Bolts, however, can remove Options/Multiples when struck.
  • Salamander MSX: In this game, Zelos is a free floating entity, and will move around the screen, spawning enemies that will home in onto you. If you can get your option stuck inside Zelos, he will be defeated very quickly. Upon his defeat, Zelos will summon Metal Slave, a very powerful Core Warship.
  • Lifeforce NES: Zelos is now protected by a snake creature, which wraps itself round him, firing the occasional fireball. This snake must be defeated before taking on Zelos. It is possible to move around Zelos, but doing this will warp the player back earlier in the game. Upon his defeat, the screen will lurch forward quickly, and the base will attempt to shut the player in - this is very hard to survive.
  • Gradius II NES: Appearing in the Boss Rush stage, Zelos will now cause the screen to flash with lightning - this is only for show - his real attack is to create several orbs that will attempt to home into you. These can be destroyed.
  • Gradius IV: Upon defeat of Berial, Zelos will appear and grow to massive proportions - he will attempt to destroy the player with a circle volley of lasers. After two volleys, he will automatically self destruct.
  • He shows up in later games, such as Gradius V as a basic enemy. They can expand their size to massive proportions. And there's a lot of them. And they go "Waaah!" when killed, just like the original.



  • In Salmander MSX, Venom is reincarnated inside Zelos and leads the Salamander Attack Force.
  • In the PC Engine port of Salamander, Zelos has a covering on his core that opens and closes constantly. This suggests that Zelos is a living mechanical core.
  • Zelos Force bears some resemblance to the Kirby character Zero
  • In the Salamander OVA, Zelos Force is seen inside the base of Salamander with a mixing stage of the "Bionic Germ" in both Arcade and the PC Engine, Apparently, he doesn't attack much at all. The Vic Vipers and the Lord British shoot the core of Zelos, which is the only thing that can stop and blow Salamander into pieces (which means in the NES and the PC Engine, you can shoot Zelos Core )

Appears In

Ships Vic ViperLord BritishSabel Tiger (Iggy Rock) • Thrasher (Zowie Scott) • Super CobraGalaxyPurple EmperorRed Devil
Salamander stages Bionic GermMeteorite SpaceRatisVolcano AreaSalamander Planetoid
Salamander (MSX) stages Top Flight Speed to LatisConduct to Space Station ZotSet the Crush Blow System - Planet EioneusSet the Crush Blow System - Planet LaviniaSet the Crush Blow System - Planet KierkeWrath of VenomCrush Salamander
Life Force-only stages Organic Speed ZoneTemple Zone
Salamander 2 stages Organic SkyArtificial SunsResident EvilBattleship ArmadaRuins of Final BaseCrystal AsteroidsDoom Fortress
Salamander bosses Brain GolemTetranIntruderFortress ValisDeathBig Core X3Jumping MoaiZelos Force
Port exclusive bosses ZylomGauInvaderGigaTutankhamonDead EndEnigmaTrue VenomMetal SlaveZelos Barrier
Salamander 2 bosses BiterHydraAbadonTenny RopPlate CoreCerberusDoom
Gradius II
Ships Vic Viper
Stages (Arcade) Artificial SunAlienCrystalVolcanoRevenge of MoaiHigh Speed ZoneBoss RushGofer Ship Interior
Port-Exclusive Stages Volcano - Crystal (NES) • Enemy Base (NES) • Gofer's Lair (NES) • Temple (PC-E)
Bosses PhoenixBig EyeGiga (NES) • Crystal CoreDeath MK IIJumping MoaiBig MoaiDesert Core (PC Engine) • Big Core MK IIZub RushBig CoreTetranGauIntruderZelos Force (NES) • Covered CoreDemosCrabGofer
End Bosses & Major Enemies
Major Recurring Foes GoferBacterionDr VenomZelos Force (Zeros)Lars EmpireGofer Sisters
Minor Enemies BrainO.V.U.M.Eleos BrainMother Computer Z Guardian CoreCentral Server Genocide CoreOuter Limits / Metal SlaveZelos BarrierDoomDark Force