The Nucleus is the boss of level 6 in the original Gradius. It consists of a pink amoeboid core and a large crystal structure formed of the same material as the rest of the stage.
The Nucleus will constantly spray random projectiles from the vents to each side of its head. Aside from that, it's only attack is to occasionally spawn Amoebas.
Nucleus makes a very brief appearance in the third episode of the Salamander anime. In the anime, it is pink colored and doesn't contain the core.
- Due to sprite limitations, the pink core of the Nucleus does not appear in the NES version of the game.
- Various lifeforms that look almost identical to Nucleus's Core (complete with a sphere of latticed webbing) appear in the background at various points in Stage 5 of Gradius Gaiden. Unlike this boss, however, these are purely background elements and do not attack the player in any way.
- In cell biology, the nucleus is an organelle that contains almost all of a eukaryotic cell's genome.
|Stages||Volcano • Stonehenge • Moai • Reverse Volcano • Wasteland (PCE) • Tentacle • Cell • Base|
|Sub Bosses||Volcano • Zub Rush • Mother and Child • Iron Maiden • Tentacle • Electronic Cage •|
|Bosses||Big Core • Cell Nucleus • Xaerous Brain|
|Space entities||Nucleus • Intruder • Phoenix (Geezer Butler) • Goliath • Bubble Eye • Wyvern • Vulture Dragon • Blizzard Crawler • Yorogaton Chimera • Gillador • Volleone • Doom • Lynyrd Skynyrd • Triumph Kicks • Gaw • Giga • Killer Dwarf|
|Body horror||Abadon • Golem • Zylom • Big Eye • Gregol • Mad Skin • Brachion Eye • Biter • Berial • Huge Heart • Crawler (X) • Infected Statue|
|Plantlife||Choking Weed • Stinger Kid • Hunter Fang • Giga's Rose • Dendrodium • Hans Naughty|
|Episodes||Episode 1: Salamander • Episode 2: Paula's Meditation • Episode 3: Gofer's Ambition|
|Characters||Ike Lord British • Dan • Stephanie McBain • Eddie Evans • Doromo • Ministers • Lee McBain • Paula • Gofer|
|Enemies||Rugal • Sharp Cross • Golem • Giga • Zelos Force • Intruder • Tentacle • Big Core MK I • Moai • Xaerous Brain • Fire Dragon • Death Hand • Big Eye • Dee-01 • Phoenix • Amoeba • Nucleus|