No need to mess around with Fallout 4's character creator to create a Snake look-alike anymore.
Clever modder Akiba91 has created a new fully-featured mod designed to bring Metal Gear Solid 5 characters into Fallout 4. It's called 'Metal Gear Solid - All in One Standalone' and it features quite a lot of little details for each one.
Venom Snake, Skull Face, and Quiet are all there. You get to choose Snake's suit, his eyepatch, bionic arm, horns and more. You can download the mod from here.
You will need another mod, called Armorsmith Extended, which allows you to create some Metal Gear Solid items on Fallout's workbench.
Take a look at some screens of the end result below: