In Metal Gear Solid 2: Sons of Liberty, the bomb disposal expert trained by Peter Stillman is known by the codename Fatman.
Fatman is a member of Dead Cell and serves as a major antagonist during the Big Shell chapter. He plants explosives throughout the facility and challenges Raiden to locate and neutralize them. His character combines bomb-making expertise with an obsession with speed, precision, and the legacy of his mentor.
Peter Stillman is an experienced bomb-disposal specialist who assists Raiden and Solid Snake’s ally Otacon. Stillman trained Fatman before the events of the game, but their relationship deteriorated. The bomb sequence therefore functions both as a technical mission and as a conflict between teacher and former student.
Fatman is often confused with Vamp because both belong to Dead Cell and appear as bosses in the Big Shell storyline. Vamp is the group’s regenerative knife fighter, whereas Fatman is the explosives expert encountered earlier in the facility.