David Leatherhoff

David Leatherhoff is the villain protagonist of the famous Half-Life mod Afraid of Monsters as well as its Director's Cut.

While David is portrayed as the game's protagonist who is simply defending himself from hordes of "zombies", it is revealed he's really been murdering hundreds of innocent people the whole time in his brutal drug overdose.

History
David is depicted as a young man addicted to drugs, and goes to a hospital to treat his addiction after receiving pills from a mysterious company. However, when washing up in the bathroom, David's obsession takes the better of him and tosses the sent pills down his throat. When he exits the bathroom, he finds that everyone has evacuated the building and the hospital is flooded with zombie-like creatures littering the halls. Armed with firearms and crowbars, David fights for his life, mowing down over 200 of hostile creatures.

Dependent on the player's actions, there can be five different endings to the game. However, they all reveal (except ending 4) that the pills David took in the bathroom made him hallucinate the creatures and he's really been a mass murderer killing doctors, patients, and other innocent people.
 * Ending 1: David wakes up in a house littered with dead bodies. Police then arrive on the scene and arrest him.
 * Ending 2: Being questioned by a police officer, David tells him that he doesn't remember anything during his drug overdose.
 * Ending 3: As a man reads a newspaper about David headlined "Psychotic Killer Claims Over 200 Lives", the real arrested David is shown to have killed himself in his cell.
 * Ending 4: David is barely saved by a group of doctors during his almost fatal drug overdose in the operation room.