The Split Head is a creature that Harry Mason encounters within the Otherworld version of the boiler room of Midwich Elementary School in Silent Hill. Upon its defeat, a shift back to the Fog World is triggered.
The Split Head faintly resembles a lizard, most suitably the extinct megalania, although its head has only extremely obscure facial features, almost making it impossible to discern parts of its face. However, black regions suggest the existence of "eyes". It walks very slowly on its four legs, especially when turning, although with its colossal size, it can cover ground quite swiftly. Its head appears to be a bloated, mutated mass. The Split Head has the ability to open up its head, or "mouth", at an incredulous, horizontal angle to reveal a seemingly toothless maw but with extremely powerful jaws.
Harry Mason discovers a fairy tale book in the school which tells a tale of a creature similar to the Split Head. The story gives Harry the knowledge he needs to defeat the monster.
- "Hearing this, the hunter armed with bow and arrow said, 'I will kill the lizard.' But upon meeting his opponent, he held back, taunting, 'Who's afraid of a reptile?'.
- At this, the furious lizard hissed, 'I'll swallow you up in a single bite!' Then the huge creature attacked, jaws open wide.
- This was what the man wanted. Calmly drawing his bow, he shot into the lizard's gaping mouth. Effortlessly, the arrow flew, piercing the defenseless maw, and the lizard fell down dead."
Its weak point, as revealed in the excerpt, is the inside of its mouth, but the beast won't expose it at first, only attacking with a powerful headbutt. The player should shoot it with the handgun until it stops and hisses, in which the Split Head's horizontal maw will faintly pull apart and compress again rhythmically. Now the shotgun becomes the most reliable weapon in the confrontation, as Harry must wait for the Split Head's mouth to gape open to shoot and actually inflict damage. The safest method would be to backpedal until the lizard's mouth opens, then shoot. Two shots from the shotgun, straight into its open mouth, are required to kill it on the Normal difficulty setting (one on Easy and up to six on Hard). If the Split Head manages to close its mouth over Harry, it will swallow him whole, eliciting a game over. Attacking with a melee weapon will result in death, as the only weapons available in the melee variety at the time are the pipe and the knife.
Another possible strategy is to run and stop a safe distance from the Split Head, then turn around and shoot as many times as possible before it gets close. Repeating this is a safe way to easily defeat the monster, as Harry is never within reach of its devastating melee attacks.
The Split Head is the hellish incarnation and transfiguration of a great lizard that appears in a fairy tale from the elementary school. The notes on the reception desk in the school state that, at 5:00, "flames render the silence, awakening the hungry beast". That and the fact that the noise heard when the player activates the boiler (changing the clock tower to 5:00) is the exact same noise made by the Split Head. This would suggest that whenever Alessa Gillespie heard the boiler when she was at school, she would imagine it to be the lizard from the fairy tale, causing its subsequent manifestation in her manifested world.
The area in which the player fights the Split Head also contains symbolism of Alessa, the burning figure in the center representing the live burning of Alessa by her mother, Dahlia Gillespie.