Stefan

Stefan is a radioactive Ghoul who was captured, imprisoned and experimented upon by the mad scientist, the Surgeon. He is caged inside the CEO offices of the Red Racer Factory in the Capital Wasteland.

Talking to Stefan whilst wearing the Ghoul Mask (received via the Tenpenny Tower quest) results in greeting you without hostility as any other ghoul does. Not much else is special about this NPC except on certain saves where he seems to prefer to squat in a awkward position on a dead wastelander.

Killing The Surgeon will make Stefan become hostile, even while wearing the Ghoul Mask.

NOTE: However on some playthroughs on the PC, this did not happen.