Master of Fasting
Very rare1.9%ObjectiveOptionalSingle-player
Complete a Mission with only the Famine Mode cheat on
Famine mode can be obtained in mission 10. After this mission, use mission select and the cheat menu to enable this cheat- then complete a mission.
This cheat makes enemies not drop any health/armor. They only drop ammo when killed with a chainsaw. Hell on Earth is probably the easiest level to do this on.
Note you cannot get this in Extra Life mode.