The Professor's Teddy Bear: by Theodore Sturgeon

 Theodore Sturgeon's bizarre story about a teddy bear which dips into the future of its human charge, causing murder and mayhem, has to be one of the first examples of the boy communicating with the man and vice versa. In this case, with diabolic intent. The messages escape safe missive form and are instead the dreams of the boy become the actions of the man. But the boy's dreams and therefore the man's actions are directed by the bear, in the best traditions of a warped toy. For the man, it means that he is in a permanent state of deja vu; which is, perhaps, the worst nightmare of all - he can remember being the boy, but the boy cannot remember being the man. The capsule of the story is the man's horror passed back to the boy. The boy doesn't understand the horror, but the bear does, revels in it, and wants more... until the man's outrage reaches back through the years and turns the boy against the bear.

The Professor's Teddy Bear finds Sturgeon at his most inventive and grotesque; it originally graced the pages of an edition of Weird Tales and is, perhaps, a story best described by reading it.