Meteor

The meteor was a Dragon disaster level threat that targeted Z-City.

Appearance
The meteor is a giant oval shaped rock.

Giant Meteor Arc
The meteor suddenly shifts its trajectory and aims for Z-City. All S-Class heroes are called to deal with it but only Bang, Bofoi and Genos responds. The meteor withstood Bofoi's missiles and Genos's full powered blast to no apparent damage. Saitama arrives and blows the entire meteor in one punch but its debris scatters across the city. Z-City is left devastated although there were no casualties.

Physical Abilities
Immense Kinetic Energy: As it is assigned a Dragon-level threat, it has the capabilities to destroy multiple cities. Even after Saitama destroyed the main body, its fragments had enough powet to ruin Z-City.

Immense Durability: The meteor was made of a highly resistant unknown material which is the reason it was able to withstand Metal Knight's missiles. It also took Genos's full powered incineration to no apparent damage.

Trivia

 * The reason why no S class were there during the meteor arc was because of the short time (35 min)..