The connecting record
shownGodzilla: King of the Monsters · 2019
Godzilla killed King Ghidorah in Godzilla: King of the Monsters.
after absorbing Mothra's energy; the body vaporised, the last head burned separately
What each of them is ranked on
The killer · Godzilla · rank 7
MonsterVerse
Framed throughout as a balancing force rather than a disaster — the films are explicit that he restores an equilibrium and then goes back to the sea. His record across four films is the most consistent on this page: he wins, he is injured, and he returns. A character written to be reliable is hard to place against ones written to be unstoppable, and the films have never put him in front of the top of this list.
shownGodzilla: King of the Monsters · 2019
Defeats King Ghidorah after absorbing a nuclear detonation.
shownGodzilla (2014) · San Francisco
Kills both MUTOs in San Francisco and returns to the ocean. — 2014
The victim · King Ghidorah · rank 5
monsterverse
The only creature the modern films treat as an equal threat rather than an obstacle: three heads that argue with each other, weather that reorganises itself around him, and a global chain of other kaiju that stand down when he calls. Beating him requires Godzilla to be given a nuclear detonation as a meal first, which is less a victory than a top-up.
shownGodzilla: King of the Monsters · 2019
Summons and commands other titans worldwide; generates severe weather.
shownGodzilla: King of the Monsters · 2019
Defeated only after Godzilla is empowered by a nuclear detonation.
What this does not settle
One death in one work. It is the only place the record puts these two in the same room, and it is evidence about that meeting and nothing wider — not a general matchup, not a rematch, and not a ranking of its own.
The ladder above it is argued from everything either of them has been shown doing; this page is argued from one citation.
Where the two disagree, the disagreement is the point, and it stays visible rather than being resolved by whichever of them happens to be on this page.