Season 4 Episode 1 of Teachers has some of the characters visiting the graves of three characters from the previous three seasons: Kurt, Brian, and Matt.
as-time-goes-by
sofia-the-first
10000-km
back-to-the-future-part-3
the-meg
adventures-of-the-gummi-bears
bad-taste
franklyn
after-earth
private-lessons
punisher-war-zone
office-space
scrooged
swordfish
end-game
the-comic-strip-presents
blood-orange
ripper-street
masha-and-the-bear
family-guy
would-i-lie-to-you
toy-story-4
man-of-steel
rise-of-the-guardians
jack-and-jill
pursued
coherence
flintstones
dream-a-little-dream
all-the-old-knives