The Subterranean People are a race of Mysterious Beings who call themselves the "True People of the Earth." Ruled by the Subterranean King, they live beneath the earth's crust and, having grown too numerous for their underground territory, launch an attempt to conquer the surface world in one of the earliest threats Saitama faces in the series.
Their invasion collapses almost immediately once Saitama defeats the Subterranean King in a single blow — without their ruler, the remaining Subterraneans surrender and retreat back underground.
Appear two different ways depending on context: in Saitama’s dream, massive muscular humanoids with three-plus eyes, jagged teeth, and tribal patterns; in reality, much smaller, frail, child-sized creatures with large bug-like eyes and wrinkled skin. Typically shown naked or in minimal ancient-style wraps.
In the dream, arrogant bloodthirsty conquerors who see surface dwellers as obstacles. In reality, opportunistic but cowardly — the instant their King dies, the entire invasion force surrenders with a handwritten “Sorry” sign and flees underground.
Claim to have lived in the Earth’s depths for generations, predating human civilization, and consider humans late-coming usurpers. Murals found in ruins beneath City Z suggest their ancestors once worshipped a colossal centipede-like monster in exchange for power.
In Saitama’s dream, they launch a full invasion of his neighborhood, giving him a genuinely satisfying fight for the first time in years. He wakes to find the real (much weaker) Subterranean King attacking his building; he kills the King with a single kick, and the rest surrender immediately. Years later, ruins discovered during the Monster Association raid reveal their ancient civilization once occupied the same complex Orochi later claimed.
Skilled tunnelers capable of emerging anywhere on the surface without warning. In the dream, strong enough to actually wound Saitama; in reality, their combat ability is negligible next to any S-Class hero.
vs. Saitama (Dream) — Ch. 4
An army of Subterraneans stormed Saitama's home in a dream sequence — the closest thing to a real, effort-based fight Saitama gets in the early series. He was winning when he woke up.
vs. Saitama (Reality) — Ch. 4
The real invasion ended the moment their King died — instant mass surrender.
Major: Ch. 4. Minor: Ch. 21, 115, 128, 131 (via ruins/murals). Mentioned only: Ch. 32, 142.
Subterranean King: their ruler and strongest fighter. Saitama: ended their invasion before it began. Monster King Orochi: his altar sat in their ancestral ruins, hinting at a historical master-servant relationship.
“We are the true people of the Earth.”
The only race in the series whose primary threat level was entirely established through a character’s dream.
🇯🇵 Japanese Voice Actors
Yamamoto, Shouta
🇯🇵 Japanese