Roger Crosses over from American Dad.

Death returns Peter to 1984 when he was 18.
When Lois enters, Brian says “18 year old Lois”.
Lois is 2 years younger then Peter so in 1984 she would be 16 not 18.

'Never Gonna Give You Up' - Rick Astley

Brian sings 'Never Gonna Give You Up' as the highlight of the dance at the country club

Back to the Future Franchise
A number of scenes in this episode spoof scenes from the films Back to the Future (1985), and Back to the Future II (1989). The basic plot is very similar to the first film, as are the dance scene and Brian's picture featuring the fading children. Brian's explanation of temporal mechanics parallels a similar scene from the second film, and the final scene, where everything is almost back to normal (the illegal alien Roger from American Dad! is present) apes the final scenes of Back to the Future.

Caddyshack

Lois walking past Peter and Cleveland and diving from the board is directly from Caddyshack featuring Cindy Morgan

"Rickroll"

Brian's cover of "Never Gonna Give You Up" was in direct reference to the recent resurgence of popularity of Astley and the song as an Internet viral ad meme known as "Rickroll", where unsuspecting Internet viewers are tricked into following a link claiming to be something that interests them, and being revealed to be a Rick Astley song, in most cases, it is "Never Gonna Give You Up"

That Chicken
The enormous chicken with whom Peter has fought three epic battles (so far!) appears briefly. But it is years before he and Peter will have their fateful first tussle over an expired coupon, so when Peter bumps him, his friend manages to calm him down and avert trouble.