Saitama vs. Mosquito

Saitama vs. Mosquito was the fight between Saitama and a mosquito.

Prelude
As Saitama is watering his cactus on the balcony, he is lamenting how powerful he has become and how now everything is too easy when a mosquito lands on the back of his hand which he then swats. The mosquito is seemingly unharmed, much to Saitama's dismay.

Battle
Saitama uses his speed to slap the mosquito all around the balcony but is unsuccessful. He tries again, but he fails to kill it. He proceeds to repeatedly try and smack the mosquito, moving so fast it appears as if he's teleporting. He later chases the mosquito on the streets with a can of bug spray, but that too proved unsuccessful.

Aftermath
After chasing the mosquito and getting some bug spray in his mouth, he meets a young cyborg named Genos. When Genos warns Saitama about the large swarm in front of them, the swarm dispatches when Genos uses Incinerate to destroy the swarm, burning Saitama's clothes and leaving him naked.