One Punch Man 3

The third season of One Punch Man.

Saitama is a hero who only became a hero for fun.
After three years of "special training," he’s become so strong that he's practically invincible. In fact, he's too strong—even his mightiest opponents are taken out with a single punch. Alongside Genos, his faithful disciple, Saitama performs his official hero duties as a member of the Hero Association.
One day, monsters claiming to be from the Monster Association suddenly appeared, taking a child of Hero Association executive hostage. The S-class heroes gather and plan a raid on the Monster Association hideout to rescue the hostage. Meanwhile, Garou, a "human monster" who was taken by the Monster Association during a battle with the heroes, awakens in the Monster Association hideout.

(Source: YouTube Description)

One Punch Man 2

The second season of One Punch Man.

Saitama is a hero who only became a hero for fun. After three years of “special training,” he’s become so strong that he’s practically invincible. In fact, he’s too strong—even his mightiest opponents are taken out with a single punch. Now, the great seer Madame Shibabawa’s prediction about the Earth being doomed seems to be coming true as the frequency of monster incidents escalates. Alongside Genos, his faithful disciple, Saitama begins his official hero duties as a member of the Hero Association, while Garou, a man utterly fascinated by monsters, makes his appearance.

(Source: Anilist)

One Punch-Man

Everything about a young man named Saitama screams "AVERAGE,” from his lifeless expression, to his bald head, to his unimpressive physique. However, this average-looking fellow doesn't have your average problem... He's actually a superhero that's looking for tough opponents! The problem is, every time he finds a promising candidate he beats the snot out of them in one punch. Can Saitama finally find an evil villain strong enough to challenge him? Follow Saitama through his hilarious romps as he searches for new bad guys to challenge!

(Source: Viz)

One Punch Man 3 Franchise