[[quoteright:224:[[VideoGame/{{Scribblenauts}} http://static.tvtropes.org/pmwiki/pub/images/Scribblenauts_-_Alien_and_Monster_2291.png]]]]
[[caption-width-right:224:[[FantasticRacism They look all the same to me. Charge the main cannon!]]]]

->''"He got an e-mail from his brother that said that [[TropeNamer aliens and monsters]] were attacking his place!"''
-->-- ''FanFic/HalfLifeFullLifeConsequences''

The integral part of the MonsterOfTheWeek episode. They are [[BizarreAlienBiology strange]], scary, and [[WhatMeasureIsANonHuman expendable]]. Some are [[OurMonstersAreDifferent different]] than what you'd expect them to be.

Of course, we can have alien protagonists and [[FriendlyNeighborhoodVampires monstrous]] [[NonHumanSidekick supporting characters]]; but the difference here is that, within the ethics of the shows that use them, it's [[WhatMeasureIsANonHuman okay to kill]] the specific threat-of-the-week version ([[FantasticRacism which is usually]] a distinct species.) There is no need to deal with [[FirstContact complicated intricacies of interstellar diplomacy to negotiate with aliens]], [[{{Transhuman}} consider ethics of advancing mankind via genetic engineering when dealing with mutants]], and [[TragicMonster listen to a vampire's tragic past to understand him better]]. This time, there are no long term negative consequences to deal with either using what [[HumansAreWarriors humanity does best]].

'''[[MurderIsTheBestSolution Violence]].'''

In short, this trope is for a specific example of BlackAndWhiteMorality when a non-human antagonist (and, likely, his entire species) is AlwaysChaoticEvil with a shallow, [[HandWave handwaved]], or PlayedForLaughs justification. Different from AliensAreBastards, in which the reasons for hostility can be elaborate and well-explained, and often the subject of much debate and comparison to conflicts among humans.

Not to be confused with the {{Creator/DreamWorks| Animation}} movie ''WesternAnimation/MonstersVsAliens''.


[[folder:Anime and Manga]]
* In ''Manga/{{Gantz}}'', the hunters are forced to fight a wide variety of enemies from this category.
* At the beginning of ''Manga/{{Bleach}}'' this is presented as how the situation is ''supposed'' to be, with shinigami sallying forth to take out the Hollow of the Week. After the first season things get a bit more complicated.

[[folder:Comic Books]]
* The very first Bizarro story by Otto Binder in ''Franchise/{{Superman}}'' assumed Bizarro to fall into this category, and he is destroyed at story's end. Fan letters quickly made it clear that Bizarro was [[ReluctantMonster much too sympathetic]] to die so ignominiously, and he was soon re-created by ComicBook/LexLuthor.
* In Creator/DCComics' ''ComicBook/LooneyTunes'' title, Lola Bunny [[BurgerFool delivers pizzas]] to ancient gods, {{Killer Robot}}s, FishPeople, and other unusual customers.

[[folder: Fan Works]]
* The fan fiction series ''[[Fanfic/TheLionKingAdventures The Lion King Adventures]]'' adopts a MonsterOfTheWeek format. Aliens and monsters crop up often:
** [[spoiler: The Inque and the Vimelea]] are alien [[spoiler: parasites]].
** The unnamed creatures in ''The Chase'' are vicious monsters who eat anyone who crosses their path.
** All of the other villains are, arguably, monsters. Particularly [[spoiler: Death and the Writer]]. Most other examples are metaphorical.
* These feature heavily in [[Fanfic/TheCalvinverse Calvinverse]] stories.

* ''WesternAnimation/MonstersVsAliens'' features [[CoolVersusAwesome this]]. It's the aliens who are used this way; the monsters are the good guys we send to fight them.
* The Franchise/{{Godzilla}} films feature various aliens attempting to take over the earth, often using some sort of giant monster to aid them in their quest for conquering the world (IE: [[Film/GodzillaVsMechagodzilla Mechagodzilla]], [[Film/GodzillaVsGigan Gigan]], [[Film/InvasionOfAstroMonster King Ghidorah]], etc).

[[folder:Folk Lore]]
* The {{Chupacabra}}, an UrbanLegend, is an alien ''and'' a monster that has been used as a menace in several TV shows and movies.
** There is a surprisingly solid theory that the first person who spotted the Chupacabra was inspired by seeing the movie {{Film/Species}}, which fits this trope possibly even better.
*** {{Film/Species}} came out in 1995. People have been talking about the Chupacabra since the 1970s.

[[folder:Live Action TV]]
* ''Series/DoctorWho'' is king of this trope, to the point where, eventually, monsters would make their way into stories in which it has no place ('The Caves of Androzani', for example, is a thriller about interplanetary politics and the ruthlessness of unfettered business practices against a weak military and political sector, with a strong cast of interesting villains in its own right...which features an unconvincing monster in a cave because, well, it's ''Series/DoctorWho'', innit?). Ironically, the show was supposed to be a historical edutainment program, until the Daleks showed up in the second story and royally [[MemeticMutation EXTERMINATED]] that idea.
* ''Series/BuffyTheVampireSlayer'':
** The show had many demons of the week. Remember that one that Buffy had to beat the crap out of, while Giles and Willow cast a spell on it?
** Inverted in an episode of ''Angel''. Cordelia has a vision about a demon and Angel proceeds to find and kill it as usual. Immediately afterwards, he finds out that the demon was actually on a mission from the Powers That Be and he should have been helping it. To be fair, he was also misled by an untrustworthy informant who told him the demon was evil.
** Actually, both aliens and monsters sorta appear on Buffy the Vampire Slayer. A grand total of one (supremely scary) alien appears in the entire run of the series, and its origin is supernatural anyway.
* ''Series/TheOuterLimits1963'' was specifically designed to [[MonsterOfTheWeek have one "bear" every week]], the producers' code term for aliens or monsters. One of the most popular episodes, [[Creator/HarlanEllison "Demon With a Glass Hand,"]] stuck the word ''demon'' in the title mostly to satisfy the network execs, who wanted a monster in every episode. There's certainly nothing demonic-looking about Robert Culp, and the bad guys are HumanAliens.
* ''Series/SpecialUnit2'' is based on this trope, combined with AllMythsAreTrue ([[ArbitrarySkepticism except]] [[Series/BuffyTheVampireSlayer vamp]][[TakeThat ires]]).
* The Reavers serve this purpose on ''Series/{{Firefly}}'', but the trope is actually more often subverted than not, as there are [[AbsentAliens no aliens]] and the characters are more likely to find themselves up against other humans than anything. [[spoiler:In the BigDamnMovie, ''Film/{{Serenity}}'', the Reavers are revealed to be once-human survivors of an Alliance experiment aimed at pacifying an entire planet's population and had the opposite reaction to the drug they pumped into the atmosphere, which instilled such apathy in everyone else that they simply laid down and died]].
* Let's not forget the antagonists in every episode of ''Franchise/PowerRangers'' ever.
* The ''Franchise/UltraSeries'' juggle with this. The MOTW is either a [[{{Kaiju}} giant monster]] or a giant alien. Sometimes a [[BreadEggsBreadedEggs giant alien monster]]. It should be noted that the titular Ultramen are aliens themselves, and many shows have a number of friendly aliens and monsters(often giant too) that show up from time to time.
* Pretty much every ''Series/{{Tracker}}'' episode.

[[folder:Tabletop Games]]
* ''TabletopGame/TechInfantry'' has vampires, mages, werewolves, weretigers, wererhinos, alien bugs, alien lions that fly, and few of them are as scary as some of the normal humans.
* ''TabletopGame/{{Paranoia}}'' has included suggestions for alien invasions alongside the [[BigCreepyCrawlies Giant Mutant Radioactive Cockroaches]]; of course, any mission in ''Paranoia'' is just a FramingDevice to let the [=PCs=] [[ChronicBackstabbingDisorder betray each other]], so...
* ''TabletopGame/{{Monsterpocalypse}}'' the factions compose of 50 foot tall monsters, which include [[AlienInvasion invading aliens]], hungry [[EverythingsBetterWithDinosaurs dinosaurs]], giant [[EverythingsBetterWithMonkeys Gorillas]], and so on...
* ''TabletopGame/{{Warhammer 40000}}'': The Holy Imperium of Man preaches this about pretty much ''all'' non-humans - Eldar, Orkz, Tyranids, Tau, even Daemons: All are evil and must be destroyed, with little to no distinction made between "xeno" species. [[HumansAreBastards They're little better themselves, though]].

[[folder:Video Games]]
* ''VideoGame/AfraidOfMonsters'' has them both in the city, due to David's drugs.
* The ''VideoGame/HalfLife'' series, natch. Primarily featured in the first game; by the second, one of the alien species had joined our side, all the others except for the headcrabs have mysteriously vanished, and most of the enemies are human cops and transhuman soldiers working for the unseen Combine, an interstellar and apparently multidimensional empire bent on universal conquest.
* ''VideoGame/WarOfTheMonsters'' features monsters being born from alien fuel, with both wreaking havoc on humanity and against one another.
* ''KidIcarusUprising'' has every single nonhuman living thing as an enemy. Even, later in the game, [[spoiler: the centurions]].

* ''Webcomic/SluggyFreelance'' has plenty of aliens, demons, and vampires the cast kill without a qualm, even though they also count several aliens, demons, and vampires among their friends. Aylee called Torg out on this when he spent his time in another dimension killing the monstrous residents in [[ComedicSociopathy sadistic and hilarious ways]].

[[folder:Web Original]]
* The ''Roleplay/GlobalGuardiansPBEMUniverse'' was full of aliens and monsters. It is a superhero setting, after all. One hero team actually fought Franchise/{{Godzilla}} for crying out loud...
* FreaksMutantsAndMonsters is a good example.
* Parodied in "[[http://www.youtube.com/watch?v=DN7C_tE8H_A The Six Monsters You'll Have For Roommates]]", a ''Website/CollegeHumor'' sketch.

[[folder:Western Animation]]
* ''WesternAnimation/{{Ben 10}}'' and its sequel, ''WesternAnimation/Ben10AlienForce''.
* ''WesternAnimation/KimPossible'': Considering the characters in the show, the Lorwardian invaders and the monsters made by a MadScientist are just icing on the cake.
* ''WesternAnimation/MartinMystery'' goes back and forth with this.
* ''WesternAnimation/UncleGrandpa'' has a few, including Emperor Krell in "Space Emperor", the Night Wolves from "Belly Bros.", the titular entity of "Funny Face", the two-headed dragon from "Nickname", the mummy from "Uncle Grandpa Ate My Homework", the alien cactus in "Jorts", and the cartoon monsters from "Viewer Special".
* Many ''WesternAnimation/SWATKats'' villains fall into this trope.