Tree House of Horror X - S11-E4
Trivia: When the Collector places Lucy Lawless inside the plastic bag, you can see Dr Who and Matt Groening (The Simpsons' creator) in plastic bags among others. (Matt's the man with the beard and glasses.).
Missionary: Impossible - S11-E15
Trivia: At the end of the episode when Betty White is asking for donations, you can see characters from many other Fox shows manning the phone lines: Bender the robot from Futurama, Hank Hill from King of the Hill, Thurgood Stubbs from The PJ's, Mulder from X-Files, and Luke Perry from Beverly Hills 90210. The owner of Fox, Rupert Murdoch,is also answering phones. The logo from Family Guy is also on the TV Betty White turns off.
Tree House of Horror X - S11-E4
Trivia: People in line for the Exodus to Mars are: Bill Gates, Ron Howard, Jimmy Carter, Stephen Hawking, Mel Gibson, Paul McCartney, Michael Jordan, Stephen Jay Gould, Michelle Kwan, Mark McGwire and Professor Frink.
Tree House of Horror X - S11-E4
Trivia: The people on the rocket to the sun are: Tom Arnold, Pauly Shore, Ross Perot, Dr. Laura, Spike Lee, Dan Quayle, Courtney Love, Tania Harding, Al Sharpton and Rosie O'Donnell.
Trivia: The couch gag in this episode shows the family in the style that Matt Groening drew them on the Simpsons on the Tracy Ullman Show.
Trivia: The cars in the Hollywood Car museum are the Munster Mobile, The Monkee Mobile, The Bat Mobile, The Flinstones' car, Herbie the Love Bug, The Dukes of Hazzard car, and The Road Warrior from Mad Max.
Kill the Alligator and Run - S11-E19
Trivia: On spring break there's a veejay named "Sepulveda" who is replaced when she gets too old by another one named "Cienega." Sepulveda and La Cienega are both the names of major streets in Los Angeles.
Trivia: In this episode the Simpsons are labeled finally as a "northern Kentucky family"; this was quickly enough dismissed as a red herring for various reasons. To further mystify, however, if you turn on the English subtitles on the episode, they say "southern Missouri family".
Trivia: Adding to the list of jokes on this show that ended up becoming true in real life, this episode made reference to a Donald Trump presidency a full 15 years before Trump first announced his candidacy for President. The episode also accurately predicted that a Trump presidency would lead to an economic recession.
Answer: I'm not sure if this is the one you're thinking of, but an episode of "Ray Bradbury Theatre," called "A Sound of Thunder," dealt with a similar matter: a group of hunters travel back in time to hunt dinosaurs, only to find things have changed when they get back because someone stepped on a butterfly.
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