The following contains spoilers for One-Punch Man by One and Yusuke Murata, now available to read in English via Viz Media.
The One-Punch Man manga has reached a sort of epilogue for the "Monster Association" arc, currently showing Saitama's recovery from battle -- which mostly means scavenging for lost items. After all, the bald protagonist essentially lost his entire place during the monsters' attack. Looking back, the fight between the two associations has been deadly and epic. Both sides spared no manpower in dealing with each other, though each also suffered heavy losses. One hero, however, isn't getting the credit they deserve.
The S-Class heroes are the very best the Hero Association has at its disposal. That is, of course, excluding Saitama. Each of these heroes possesses noteworthy battle prowess, though they also have a their own interesting quirks. Pig God is essentially the quiet and gluttonous type; he doesn't care much about hierarchy or keeping up appearances, but he does care about keeping his stomach full. Even so, he does care about saving people and doing his duties as a hero. His exploits during the One-Punch Man's recent war against the monsters are proof of that.
Pig God: The Big Eater Who Ate The Big Eater
Before the S-Class heroes started their raid on the Monster Association lair, they gathered around to decide their strategy. Pig God's only contribution at that time was finishing his snacks while passively listening to their action plan. However, he was immediately put into action the moment the raid began; Pig God's first major battle is against Big Eater, a ginormous monster that boasts of its eating capabilities. But before Big Eater can show off its moves, the poor monster is swallowed whole by the gluttonous hero, saving Atomic Samurai's disciples in the process. Pig God's primary fighting style is consuming his opponents. No matter how big they are, he can somehow swallow them whole.
However, Pig God met his match in the Monster Association Executive Gums. The monster with a gaping maw has a similar ability in that it can swallow virtually anything -- including Pig God himself. The hero may not have won against Gums, but the monster also fails to win the day. After being swallowed whole, Pig God attempts to eat his way out of the monster's belly. Gums can feel the hero's maneuvers and is forced to regurgitate his meal. Unfortunately, the two will never get to settle the score as Gums already lost its life at Barf President Ugly's hands. Still, Pig God was able to consume Gums' remains in his attempt to recuperate energy.
Pig God's Big Stomach Saves Lives in One-Punch Man
Pig God's mouth may be an overpowered asset in One-Punch Man, but its utility in combat is rather limited; his failure to defeat Gums is proof of that. However, his incredible swallowing ability excels in another area -- rescue. When Terrible Tornado uprooted the Monster Association's lair, Pig God stayed underground to search for overlooked heroes. He manages to find and swallow Zombieman, Atomic Samurai's disciples, and Narinki's private squad. Upon resurfacing, he shields Child Emperor from falling into rubble. Pig God then regurgitates all of them safely and soundly.
The fight with President Ugly saw Pig God team up with Tank-top Master. The gluttonous hero plunges into danger just as President Ugly is about to finish off Narinki's private forces, immediately shoving them into the safety of his stomach. Tank-top Master then throws them out of battle and into safety. He does that again when Evil Mineral water is defeated, causing a massive tidal wave and using Centisennin's massive corpse as a ramp to reach the other heroes. Just like in the other scenarios, Pig God swallows around 20 others -- including Superalloy Blackluster, Puri Puri Prisoner and Tank-top Master. If not for him, these S-Class heroes may have drowned to their deaths.
Pig God Is One-Punch Man's Thoughtful and Voluminous S-Class Hero
Ever since Saitama knocked some sense into Garo with his Zero Punch, the fight between the two associations has virtually come to an end. Everybody at the scene is taken in by Metal Knight, who had previously been missing in action. The S-Class hero will be using his advanced technology to get rid of any radiation they acquired while being in Garo's proximity. After getting treatment from Metal Knight, the other S-Class heroes are then taken into the med lab to recuperate from their heavy injuries. However, one S-Class hero decides to do otherwise.
While the others are getting treated, Pig God is convinced his role in the battle isn't over yet. He returns to City Z, where the epic battle was held, and a Hero Association helicopter sees him digging through the rubble. When he is called out, he starts running, forcing the A-Class hero Ayer to make a move. Ayer plans to force Pig God to return to the laboratory -- but before he can do so, a puddle-sized Evil Mineral Water appears.
Ayer shifts his attention from the S-Class hero to the monster. He throws his boomerang at it, but Evil Mineral Water shoots through it and pierces Ayer's neck. Pig God takes that opportunity to lunge at the monster and swallow it. In its final struggling attempt, Evil Mineral Water riddles Pig God with multiple holes. However, its efforts are futile as Pig God manages to digest it before collapsing from the injury he suffered.
Evil Mineral Water was thought to be dispersed by Saitama's Serious Punch, but it turns out the monster survived it. If Pig God overlooks its existence, it can easily recover by integrating into bigger bodies of water. With most of the heroes currently out of commission, the emergence of an ocean-sized Evil Mineral Water could cause massive damage in the world of One-Punch Man.