The "Hook Man" was an enemy that appeared in the E3 2003 live demo and trailer for Resident Evil 4. The iteration of the game's development it appeared in was consequently referred to as "Hallucination ". While the enemy appeared prominently in advertising, it is suggested it was not expected to appear in the final game at all, simply existing as a means of showing special effects and the QTE system.
When Resident Evil 4 departed from "Castle" and into "Hallucination", the script was recycled while awaiting alterations. Continuing from Castle, Leon was to be infected with a virus; in Hallucination, it was decided the player should experience his hallucinations.
As shown in the E3 2003 demo, Hook Man would emerge from a painting when Leon starts to hallucinate. Armed with his namesake hook, he would teleport to reach Leon faster and deliver surprise attacks. It was decided Hook Man would be vulnerable to light, allowing the player to weaken it.
In the ending of the demo, which is ripped from the Biohazard 4 trial, the "Thank You for Playing" message featured a concept art that presumably belonged to the Hook Man. The artwork in question featured a man with white eyes that are slightly asymmetrical (specifically, his right eye is slightly higher than his left eye). A similar illusive effect on his face can be seen in the actual game-play footage.
- According to Yasuhisa Kawamura, the concept of the Hook Man, and to a greater extent the entire idea behind the Hallucination build, was derived from a scene in the 2000 American horror film Lost Souls, where Maya Larkin (played by Winona Ryder), proceeds to have a hallucination of her being in a derelict building with a killer on the loose while washing her hands.