George Bates was a human who was abbandoned by his parents and grew up in the seweres and mutated into a shapeshifting mutant due to contaminated food and filthy water found under ground (particularly mice and strange serpent like creatures). He was born from a welthy and rich family and his brother Norman was in a college when he was only a baby. The monster descovered that his brother had returned home and killed his mother. He eventually started eating the bodies of the victims that his psichopatic brother would through to him after having attracted them to the motel that he built. One night Norman wanted to kill a girl called Janet but the monster was in love of her so he killed him. Without his brother the monster could not feed on any human beings so he started to come out and kill people himself. Janet called Private investigator Dylan Dog to uncover the truth of the deaths but due to her past of insanity no one believed her and she was sent to an asylum from where she had previously escaped, Dylan non the less started to searche and met the monster underground, at first George was friendly to Dylan but soon descovered that Dylan was killing time waiting for the chance to escape, he then showed Dylan that Janet was hiding with him in the seweres, she and the monster tried to kill Dylan but Janet accidentally decapitated George, killing him, and she then ran to her death by falling inside a hole. Dylan survived without knowing that Janet herself was mutated like George and continued feeding on people staing at the motel.
The name of Norman Bates and the motel are a clear reference to Alfred Hitchcock's Psycho.