.
Two stories in the award-winning DANGEROUS VISIONS short story collection, edited by Harlan Ellison:

"A Toy For Juliette" by Robert Bloch.

and expanding from that,
"Prowler in the City At the Edge of the World" by Harlan Ellison.

Both self-contained stories that can be enjoyed individually.
Although Ellison's follow-up story was directly inspired by and expands on Bloch's, if you choose to enjoy the combination.

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