5. Diamond Dog's Alternate Fur Colour Resembles The Foxhound Logo
Once Diamond Dog matures into an adult and therefore a buddy member of your unit, he can be brought out into the field and his colour even customised. One of the swatches is a light brown-orange colour, which to long-standing MGS fans will near-instantly make them think of the Foxhound logo, which of course features a very similar-looking fox holding a knife in its mouth. It may not be the most complex or clever Easter egg in the entire game, but heading out into battle with this bada** creature is a true joy.