"Storytime Simon" is the alias of the narrator of The New Squirrel series of holotapes.
Behind the scenes
Storytime Simon and the holotape series The New Squirrel is a reference to the once popular children's toy Teddy Ruxpin. The narrator of the stories, Storytime Simon, sounds similar to the toy and all the holotapes are found next to Teddy bears.
Storytime Simon is mentioned only in Fallout 4.