"The Cobra Unit, also known as the Cobras and once referred to as the Sons of The Boss, was a legendary team of soldiers that were assembled by The Boss in 1942 to combat the Axis Powers. The codenames for each member of the team reflect a specific emotion that a soldier experiences while on the battlefield.

The Cobra Unit was one of the many superhuman soldiers that the Philosophers had formed through their resources.

In 1942, the Cobra Unit was officially formed and led by The Boss (then known as The Joy) during the Battle of Stalingrad. The Cobra Unit consisted of soldiers trained to win the war and with superhuman abilities - which at least two owed to parasite therapy. Its members were The Pain, The Fear, The End, The Fury, and The Sorrow. Because of each of the members of the unit being extremely loyal to The Boss, to the extent that they only obey her orders even when she is under the command of someone else, they are sometimes referred to as the Sons of The Boss.

During the D-Day landings at Normandy (June 6, 1944), the Cobras were sent on a mission to destroy several V2 rocket installations. During the war, the Cobra Unit was used for the nastiest kinds of wet works, the kind that could never be let out into the open. Their missions were so top secret that not only were they forbidden to be taken prisoner, they couldn't even leave their corpses behind. Because of this, they carried a microbomb with them on their missions, which would automatically detonate upon their deaths. During D-Day, The Boss gave birth on the battlefield to her and The Sorrow's child, who was taken away by agents of the Philosophers.

The Cobras were later officially disbanded in 1947 due to tensions between the Philosophers.

In 1962, The Boss was forced to execute The Sorrow, otherwise both the American faction and the Russian faction of the Philosophers would have executed their son if both of them have lived."