the story: A little girl's imaginary friend becomes real.
similar to: "The Bonding" (Next Generation), "Alter Ego" (Voyager), "Exile" (Enterprise)
my thoughts: A great deal similar to "The Bonding," in which a little boy is manipulated by aliens, "Imaginary Friend" is another tangential Alexander story (there were a ton of these after he becomes a recurring character in "New Ground" during the fifth season...) proving that maybe the series didn't really know what to do him after all. I mean, it's odd that they were still doing a "Bonding" episode with a recurring boy in the cast line-up and not have him in the lead.
Yet it's not a complete waste, because the kid in the lead is played by the precocious Noley Thornton, who would later appear in Deep Space Nine's "Shadowplay" in a much better story.
But as you can see above, this kind of story was a franchise trope, and a season that otherwise was packed with excellent episodes sometimes had to fall back on old standby material to pad itself out. That's what "Imaginary Friend" basically is, padding. Watch it if you're a season completest, but otherwise you can certainly consider skipping it...
Brian Bonsall (Alexander)
Whoopi Goldberg (Guinan)
Patti Yasutake (Ogawa)