The Boss, also known as The Joy, The Mother of Special Forces and Voyevoda (Russian for "Warlord"), was the "final child of The Philosophers and the mentor of Big Boss. She was the founding leader of the Cobra Unit in which she was known as "The Joy," however, when they were disbanded at the end of WW II , she was granted the codename of the Boss Together with Big Boss, she developed the technique of CQC.
Despite "The Joy" being her former code name, The Boss rarely smiled during the events of Operation Snake Eater. In contrast, The Sorrow always smiled during his encounters with Big Boss, with not one occasion where there was a frown on his face.
The Boss also had a lot of love and care for her apprentice Big Boss and may have thought of him as her own son. She also protected him during Operation Snake Eater from Ocelot (her son) and EVA by making them promise not to kill him, and she instructed EVA to tell Big Boss the truth behind her final mission and death as she wanted him to know. The Boss knew that He would feel guilty for killing her so she told EVA to tell him to forgive himself and to let it go.
The Boss also possessed a tremendous amount of physical strength, evidenced by her carrying the containers for the Davy Crockett launcher and the two Davy Crockett shells, which in combined weight would have exceeded 300 kg (nearly 700 pounds) late into the Virtuous Mission, and presumably fire it by hand at Groznyj Grad late into Operation Snake Eater.
The Boss also had a great amount of loyalty to her country; So great, she let her government use her ruthlessly and knowingly have her killed by her apprentice Big Boss. She is not blinded by her loyalty to her country to the extent that she didn't know how soldiers are used, as she mentions to Naked Snake when they re-encountered each other after five years.
She was also one of the few members of Groznyj Grad to be allowed access to Groznyj Grad's weapons lab's west wing in spite of being below Colonel-class.
She is voiced by Lori Alan.