Metal Gear Solid 4: Guns of the Patriots

Missable Laughing Octopus is the boss you will face during Act 2: Solid Sun. See the spoilers below as it is part of the story.

The encounter will initiate after you have defeated the FROGs Unit that will appear in the laboratory. You must defeat her non-lethally. This means that you must deplete her Psyche bar and not her Health bar. The Psyche bar is the small, thin line below the Health.

As soon as the fight starts, run out of the room and take cover from her machine gun. When she stops shooting, fire at her with the Saiga-12. Using V-Ring will make it non-lethal. Never exit to the outer hallway immediately, as she may jump through one of the windows and deal damage to you. Wait a while and then go to seek her hiding place. Having the Night Vision activated will reveal her immediately as the stealth camo can’t protect her from that. Keep playing safely and follow this strategy to deplete her Psyche.

When the fight with the Beauty starts, head to the bed in the laboratory and you will get the doll.