One Punch Man season 3 is going all-in on the Monster Association arc. It’s a massive stretch of the manga (nearly 100 chapters), stacked with villains, and the anime says it’s adapting the whole thing. With season 3 dropping October 12, 2025, here’s who Saitama will be punching through and why this arc is such a big deal.
What season 3 actually covers
The show is tackling the Monster Association arc from top to bottom. That means a flood of monsters, a deep bench of weirdos and heavy hitters, and a storyline that runs parallel to a lot of the Hero Association’s own mess. It’s a big swing for the anime, and if you’ve heard fans call this the series’ most crowded and chaotic run, they’re not wrong.
So, what is the Monster Association?
They’re not just a clubhouse for baddies. The Monster Association is a full-on organization with a goal: break the Hero Association. They do it by terrorizing cities, snatching high-value hostages tied to the heroes, and forcibly turning powerful humans into monsters to build their ranks.
The public face of the group is Monster King Orochi. The secret brain behind it is Psykos, who keeps things running from the shadows.
How their power ladder works
Internally, there’s a hierarchy: the leader at the top, then executives and associates, then middle management, and yes, even a treasurer. Inside baseball detail: disaster levels like Dragon, Demon, and Tiger show up here, but those are threat ratings in the One Punch Man world, not job titles. Within the association, Gyoro Gyoro (also written as Gy Gyoro) assesses members and tags their danger level, which feeds into the pecking order.
The heavy hitters you should watch
God: the series’ most mysterious presence. Different people see different forms, but the thing that matters is power. God can grant it, amplify it, and even exert control. He’s the reason the Homeless Emperor is so dangerous, he’s tied to the fusion of Orochi and Psykos, and he factors into Garou’s rise. If there’s a puppet master in this arc, this is the one.
Orochi and Psykos: the Monster Association’s leaders. In their normal states, Saitama took down Orochi and Tatsumaki handled Psykos. But when they merged, their power spiked hard — enough to fight Tatsumaki on basically even footing. That fusion is where things get nasty.
The Monster Association roster (beyond the top)
Outside of the headline monsters, the group is loaded. Some of these names are Dragon-level nightmares, some are Demon or Tiger threats, but they all help turn this arc into a war zone:
- Black Sperm
- Gale Wind
- Awakened Cockroach
- Destrochloridium
- Elder Centipede
- Hellfire Flame
- Baquma
- Electric Catfish Man
- Evil Natural Water
- Phoenix Man
- Bug God
- Maiko Plasma
- Fuhrer Ugly
- Bakuzan
- Building Booper
- Marshall Gorilla
- Gouketsu
- Devil Long Hair
- Master Joe
- Gums
- Do-S
- Sludge Jellyfish
- Homeless Emperor
- Eyesight
- Nyan
- Face Ripper
- Overgrown Rover
- Fist Fight Djinn
- Free Hugger
- G5
- Hundred-Eyes Octopus
- Rafflesidon
- Super Mouse
- The Three Crows
- The Great Food Tub
- Unihorn
- Vampire (Pureblood)
And then there’s Garou
The arc’s final boss isn’t technically a Monster Association suit, but he’s the name everyone is waiting on. Garou is the closest thing Saitama gets to a true rival this season — a martial arts prodigy trained by Bang who decides the Hero Association is hypocritical and makes it his mission to tear down the idea of heroes altogether. He’s got a childhood grudge fueling him, and by the time he collides with the S-Class, he’s evolving so fast most of them can’t keep up.
By the time he runs into Saitama, Garou has become a raging, almost demonic force. The showdown is exactly what you want it to be. Who wins? You’ll find out when the season lands.
Release date and where to watch
One Punch Man season 3 premieres October 12, 2025, with the Monster Association arc as its full focus. If you want to catch up, the anime is currently streaming on Crunchyroll.