As if “Stranger Things” didn’t already have enough ’80s pop culture in its DNA, Jimmy Kimmel took it even further with a teaser for the mock spinoff series “Perfect Stranger Things.” In the clip from Monday’s episode of “Jimmy Kimmel Live!” Larry (Mark Linn-Baker) and Balki (Bronson Pinchot) get a third roommate named Dem O’Gorgon (Kimmel, in a pretty convincing costume), adding a dose of streaming-era sci-fi to the TGIF sitcom.