The Pain

The Pain appears in the game Metal Gear Solid 3: Snake Eater and is a member of the Cobra Unit.

He has the ability to control large swarms of hornets at will. He gained this ability by allowing hornets to sting him for days on end and for months at a time, until the hornets came to believe that he was one of their number. As a result of this, his face is covered with weals from the stings. He is also said to carry a Queen in the pack on the back of his hips, using her sound to guide the hornets. Additionally, he carries a large array of vials on his vest, which he flings at enemies to guide hornet swarms at them.

Besides his hornets, The Pain is armed with a Tommy gun and grenades, and can use hornets in conjunction with these weapons. He can protect himself from gunfire and other attacks by covering himself with a thick shield of them, and can create an exact duplicate of himself, shaped out of hornets, to confuse his enemies.

He also raises special hornets called "bullet bees" inside his own body. When he removes his balaclava, the bullet bees are released from his mouth. They move at extraordinarily fast speeds, and upon contact with enemies, they burrow into their bodies and begin eating their insides until they are dead.

His codename signifies the pain he feels while on the battlefield.

The Pain was ultimately defeated by Naked Snake in a battle in an underground cave. Upon his defeat, he activated a microbomb like that all the Cobras carried, destroying his corpse and his entire swarm. He was the first Cobra to fall.

Walkthrough
As soon as the battle starts, wait for The Pain to throw the feramones, once he is about to throw them, roll off of the rock and you should be directly below The Pain. Try to shoot his head a few times to trigger the hornets, who come and protect him, and if you can't hit his head, try his body several times. Once the hornets arrive, throw a Grenade directly above. Once the grenade expodes aim and shoot at his head, and if he moves than shoot his body. When Phase II of the battle starts stay in the water because he will start to shoot his bullet bees. After the bullet bees, he will throw some grenades in the water without the help of his hornets, when he does swim as far away as Snake can. Once you have avoided the attacks, resurface and throw a grenade and aim for his head. A reminder, when the battle begins, Phase I, make sure to shoot him and not give him a chance to get the Tommy Gun. If he does swim away, and sometimes you can use some of his attacks to your advantage, like when he summons the hornets to attack you with a grenade. If you shoot him before the hornets leave his rock, you might be able to hurt his shield.

Hideo Kojima revealed, in an exclusive interview for Japan's Famitsu magazine, that The Pain's forename is Claude.