Origin: Silent Hill 3
Appearance: The Insane Cancers are obese creatures without a very well defined anatomy. They look like giant raw bag of meat, fat and swollen. This creatures usually are lying on the ground without attack the character. They are just resting there, a lazy mass of meat. However, they are far more dangerous than could look if approached, and deadly fast. Without a strong weapons the death is the most certain end. These bulbous and malformed creatures attacks fast using their little arms using all their fat body. Luckily in most of the case they can be easily avoided while sleeping on the floor. Unluckily, sometime their giant body are an obstacle impossible to avoid and they must be killed.
Symbolism: The Insane Cancer could easily symbolize what the name already suggests: a giant tumor growing from the insane psych of Silent Hill itself. But, in the canonical Silent Hill franchise, usually the creatures are tightly related to the mind of the main characters. They are the personifications of their hidden fears, their anxieties and failures. So, talking about Silent Hill 3, what is happening to Heather that could be so disturbing to give shape to the Insane Cancer? Well, for example she is pregnant of a pagan God. And what is a fetus? Something that is growing inside her body, taking a shape and a specific anatomy. But for Heather this is an unwanted pregnancy, she is young and not ready for the consequences, even if the father was not an evil God. From this fear and anxiety born the Insane Cancer, something deformed that grow and consume like a cancer… or an unwanted baby. This adult fear of maternity, in my opinion, is what is symbolized by this monster. Even more strange, while wearing her secret costume Heather can meet a mysterious Insane Cancer that speaks Japanese as a robot.
Very weird stuffs in Silent Hill,here you can see the video.
Surreal and Creepy 