Shelfis was Benjamin's imaginary friend. He found him in summer of 1990, after the train accident. He said he lived behind the Masons' house. Shelfis would come visit Benjamin at night after we had gone to sleep. He also played with him outside during the day. Sometimes he went with him to Nonnie's (B's grandmother), but not to Gram's (B's babysitter). Sometimes he was even in the car with us.
When I asked Benjamin to describe him, he couldn't, because he was invisible (of course!). I told him that my imaginary horses were visible to me, but he said he couldn't see Shelfis either. He couldn't tell me where the name came from either. I am sure he was a byproduct of the train accident, along with The Ugly Man. I imagine he was Benjamin's protector. When we moved to Denver, Shelfis stayed behind.
See separate posts about the accident and the ugly man.