A sub-trope of Paranormal Episode and Bizarro Episode, wherein the bizarre happening involves space aliens visiting Earth, for one reason or another.
Examples:Anime & Manga
- Episode 22 of Excel Saga sees the Earth under attack from Puchus (who are revealed to be a race of galactic conquerors), which the show promptly uses to cram the episode choke-full with shout-outs to classic Space Opera anime series like Space Battleship Yamato, Mobile Suit Gundam, and Captain Harlock.
- Axis Powers Hetalia had the movie "Paint it, White" where the nations try to ward off the threat of human extinction from the alien race known as Pict, who seek to transform mankind and drain the color from the world.
- The Tintin story Flight 714 starts out normal enough, when Tintin and his friends are kidnapped by Rastapopulus's henchmen and kept prisoners on a small Indonesian island. But it soon become clear that something weird is going on, and it turns out that aliens have been coming to the island for millennia. And yeah, everybody except for Snowy forget all about the adventure due to Laser-Guided Amnesia.
- Asterix and the Falling Sky is basically its equivalent in the Astérix franchise. Two kinds of aliens (an Expy of Mickey Mouse and his Superman Expy bodyguards vs Manga-like insectoids and robots) fight over the right to get the magic potion. And yep, it ends with the good toon-like aliens erasing the villagers' memories of this episode.
- The Indiana Jones series typically revolved around religious and mythological artifacts; but Indiana Jones and the Kingdom of the Crystal Skull involves Indy chasing after the crystalline skulls of Ancient Astronauts.
- The Benson episode "Close Encounters on the Third Hole," wherein the Governor thinks a bright light he saw while golfing was aliens abducting Benson.
- The Miami Vice episode "Missing Hours" — the otherwise normal TV series sees lots of weirdness, including a woman claiming her deceased husband had been abducted by aliens and Crockett and Tubbs later see a UFO.
- The MacGyver episode "The Visitor" has our hero dealing with mysterious happenings involving apparent flying saucers. At the end, he can't quite explain what it was which was seen.
- Baywatch Nights had an episode, "Symbol of Death," where Mitch and Ryan deal with a man who insists an alien invasion has long been underway.
- Soap: A Story Arc involves Burt being abducted by aliens, who send an alien disguised as Burt down to Earth.
- Quantum Leap: Sam leaps into a man who claims to have seen aliens, and as of the end of the episode it appears it might be true.
- Played with in Murdoch Mysteries: The episode entitled "The Annoying Red Planet" starts with a seemingly impossible crime (a corpse hanging in a tree with no footprints leading up to it), and quickly brings in locals' reports of strange noises and lights, crop circles and strange footprints. Constable Crabtree seems quite convinced that aliens (specifically Martians) have visited, but Murdoch is convinced everything has a mundane explanation. It turns out Murdoch is right, but the truth involves some advanced new technology, and there is a conspiracy to make people think aliens are about the place.
- The Buffy the Vampire Slayer episode Bad Eggs has the crew fighting a nonparanormal parasite — one of earthly origin, but decidedly alien-like.
- The season 3, episode 8 crossover of Supergirl, The Flash, Arrow, and Legends of Tomorrow was titled "Invasion!" and dealt with the alien species The Dominators attempting to invade and conquer Earth.
- The Mario & Luigi games, (and by extension the Super Mario Bros. franchise), have one installment Mario & Luigi: Partners in Time where aliens known as Shroobs invade the Mushroom Kingdom.
- Scooby-Doo usually chases after (fake) ghosts, mummies, werewolves, etc. But in Scooby-Doo and the Alien Invaders, the gimmick is aliens — complicated by the fact that there are not only bad-guy humans pretending to be aliens, but also good-guy actual aliens pretending to be Earthlings.
- In 2007, Cartoon Network had a "CN Invaded" crossover event involving several different series (Foster's Home for Imaginary Friends, Ed, Edd n Eddy, My Gym Partner's a Monkey, Camp Lazlo, and The Grim Adventures of Billy & Mandy) having episodes involving an Alien Invasion.
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