Unlockables
Chicken Hat
When you die several times in short order, you'll gain the option to equip a special piece of gear called the Chicken Hat. While this is equipped, enemies won't engage with you no matter how obvious you make your presence. Instead, they'll pass out while standing. However, it only works three times in a given mission before disappearing on the fourth use, and you won't be able to rank higher than "A" on that particular run. You can enable or disable the special gear from the Options menu, while the game is paused.
Ground Zeroes - Mother Base Staff
When you rescue Persons of Interest and Prisoners of War in Metal Gear Solid V: Ground Zeroes, you can save your file from that game's main menu and then download it from the main menu in Metal Gear Solid V: The Phantom Pain for various rewards. The prisoners you rescued will appear at Mother Base as one of your rewards. Known prisoners include the following:
- HIDEO - Diplomat who appears following Missions 3, 4, and 5
- OCHRE CHAMELEON - Appears following Missions 3, 4, and 5
- GRIZZLY HEDGEHOG - Appears following Missions 3, 4, and 5
- HUNGRY CROCODILE - Appears following Missions 3, 4, and 5
- WILD HARRIER - Appears following Missions 3, 4, and 5
- FINGER - Appears following Mission 6
- EYE - Appears following Mission 6
- GRAY WALLABY - Appears following Mission 6
- BLUE CHAMELEON - Appears following Mission 6
- MIDNIGHT MASTIFF - Appears following Mission 6
- WILD STALLION - Appears after two of either Missions 7, 8, or 9
- MAD WALLABY - Appears after two of either Missions 7, 8, or 9
- ASSASSIN HARRIER - Appears affter two of either Missions 7, 8, or 9
- HUNTING STALLION - Appears after two of either Missions 7, 8, or 9
- FRIGID MONGOOSE - Appears after two of either Missions 7, 8, or 9
- CRYING STURGEON - Appears after two of either Missions 7, 8, or 9
- BITTER CENTIPEDE - Appears following Mission 12
- ROARING CAPYBARA - Appears following Mission 12
- PIRATE CAPYBARA - Appears following Mission 12
- NIGHT TREE FROG - Appears following Mission 12
Ground Zeroes Save Transfer Rewards
If you played Metal Gear Solid V: Ground Zeroes, you had the option to upload your save file from the main menu. When you play The Phantom Pain, you can download that save, also from the main menu, and you will receive the following rewards:
Metal Gear Solid 1 Skin - Snake looks similar to his appearance in Metal Gear Solid on the original PlayStation
Ground Zeroes Sneaking Suit - Available as a special upgrade through the Mother Base
Gold Bionic Arm - Only available if your save was made after you complete Mission 5: Over the Fence and rescue the Bionic Engineer
Note that you can also transfer data from the PS3 version of Ground Zeroes to the PS4 version of The Phantom Pain, or from the Xbox 360 version to the Xbox One version.
Easter Eggs
Paz Lives!
After the Medical Strut has been constructed, make your way to the top and you'll spy a door with a blue light. Inside that room, you'll find a "Work in Progress" sign to your left. Head right instead, where you can enter another door to find Paz. From there, it's possible to have additional interactions and uncover new information as the game progresses.
Smelly Snake
Complete enough missions without returning to Mother Base, and you'll eventually see flies swarming around Snake. When you finally do head back to Mother Base, people will greet you if you get close but also will try to avoid you. When you talk to Ocelot, he'll say "Snake, you stink" and will dump a bucket of water on you.
Silent Hills in Africa
If you played PT, the demo that was released to promote Kojima's now-canceled Silent Hills project with Guillermo del Toro, you likely heard a recording that outlines a horrific murder. In Metal Gear Solid V: The Phantom Pain, you can find and listen to that same recording. Look for a radio positioned on the floor near one corner of a tent, just beyond an outpost encampment in Africa (it's near the site of Mission 20: Voices).
Rescue Hideo Kojima
You can rescue Hideo Kojima, the creator of Metal Gear (and this game's director), in the Side Op 112 Intel Agent Extraction mission. Once you have done so, he'll head back to the Mother Base.