Dr. Shreek is hired to be Jerry Hawkin's piano teacher after he discovers an old piano in the attic. When he introduces himself, Shreek appears to be a jolly old man, resembling Santa Claus. He even pokes fun at his self proclaimed unusual name. Shreek takes an obsessive interest in Jerry's hands. He studies them thoroughly, calling them beautiful, wonderful hands. He tells Jerry if his lessons go well and his hands are deemed "ready", he will be allowed to continue them at his personal music School. Shreek's interest in his hands unnerves Jerry, and he begins to having nightmare involving him. Jerry makes impressive progress with his music, which pleases Shreek greatly. He permites Jerry to come to his School.
When Jerry does, he finds something unusual about the place, and is told stories about children who went missing there. After Jerry arrives for his final lesson, Shreek flies into a rage upon hearing that Jerry is quitting. He tells Jerry that he needs his hands, and chases him across the School. The secret behind Shreek's obsession with hands is revealed when Jerry discovers disembodied humans hands playing piano in the recital hall. Shreek attacks Jerry but he is stopped and shut down by Mr. Toggle, the school's janitor. This reveals to Jerry that Shreek was simply another one of Toggle's many robots.
Shreek is described by Jerry as looking very similar to Santa Claus. He has a white mustatche, and bright red face. It can be assumed he was deliberately designed by Toggle to look friendly. Despite being a robot, Shreek is very human-like in his mannerisms. Toggle describes him as his best robot yet.
Shreek's personality changes throughout the book. When he first introduces himself to Jerry, he is a jolly, kind old man. However, he takes an eerie interest in Jerry's hands. Shreek's kind demeanor changes into a crazed frenzy when Jerry tells him he no longer will be taking lessons. Shreek chases after Jerry, even hurting him in the process.