[[quoteright:350:[[Franchise/StarTrek http://static.tvtropes.org/pmwiki/pub/images/eveolutionaryretcon_7735.jpg]]]]
[[caption-width-right:350:On the left, Commander Kor in "[[Series/StarTrekTheOriginalSeries Errand of Mercy]]". On the right, Commander Kor in "[[Series/StarTrekDeepSpaceNine Sword of Kahless]]", twenty-five years later.]]
->''[[Franchise/StarTrek What's up with these Klingons?]] [[StarTrekTheOriginalSeries Remember in the day?]]\\
[[HumanAliens They looked like]] [[PlaysGreatEthnics Puerto Ricans]] [[SpaceClothes and they dressed in gold lamé]]\\
[[DarkerAndEdgier But now the look like heavy metal rockers from the dead]]\\
[[SpandexLatexOrLeather With leather boots]] [[AlienHair and frizzy hair]] [[RubberForeheadAliens and lobsters on their heads]]''
-->--{{Music/Voltaire}}, ''The USS Make Shit Up''

Over the course of time, advances in special effects technology and make-up techniques can allow a series to have bigger and better creatures and monsters. Often, the original version of a creature might not have been that cool or interesting, and so a new model was established using the more advanced technology. In other cases, technological advances can't be credited for the retcon: sometimes a creature's look will change as a series progresses due to ArtEvolution.

This is often seen in fantasy or Sci-fi media.



[[folder: Comic Books ]]

* Generally, early characters costumes will be retconned to be more realistic and sensible in favor of the bright colored spandex and cuffed buccaneer-style boots look. Superhero costumes historically appeared to draw inspiration from the form-fitting costumes worn by gymnasts, circus strongmen, and acrobats. While such outfits are sound for strictly athletic purposes, they provide little in the form of body protection. In more modern times, costumes will be more functional and less like costumes. Footwear will be sturdy and made for rough use. The actual reason that comic book characters wore so much spandex is due to the fact that artists found the human figure easier to draw nude than with clothes. Drawing the nude figure is a basic skill drilled into the artists early on. Drawing clothing and folds in cloth may take much longer to master and render. These points are especially significant since comic book artists often had to produce completed art much faster than they do now. They simply did not have the time or resources to create elaborate highly detailed costumes. Especially when they knew that much of their fine detail would be lost druing image reduction as well as in the cheap printing processes of the time. The reason for the bright colors, of course, was due to the fact that until recently, comic books were printed in four colors (the CYMK color model). Also, in most cases, black was neccesarily substituted with blue due to the fact that black would appear too flat in print. SpiderMan's costume, for instance, was originally intended to be red and black, not red and blue.
** The XMen costumes have undergone numerous changes when retelling stories set in the early years of the yellow and black outfits. The film, ''Film/XMenFirstClass'', for example, retcons those costumes as military flight suits and the yellow is somewhat understated.
** {{Captain America}}'s original costume was what appeared to be the traditional spandex tights with buccaneer boots. Retcons of his 1940s adventures have reimagined the costume as a more sturdy militaristic outfit with pouches and hard protective headwear in place of a cowl and sensible combat boots in place of red buccaneer boots.
** {{Batman}} started as the spandex clad caped crusader. Starting with TheNineties, artists and writers have experimented with making his costume more plausible and sensible given the beatings that Batman takes in the course of his adventures. This evolution ultimately resulted in realizing Batman's outfit as a heavily armored, high tech suit that employs military issue polymers created by Wayne-Tech. Even the cape is now actually functional and allows limited gliding.


[[folder: Film ]]

* The xenomorphs from the later ''Franchise/{{Alien}}'' films are much more insectile and predatory than [[Film/{{Alien}} the original film]]'s man in a suit version.
* An inversion occurred with the ''Franchise/StarWars'' prequels. When he first appeared in ''Film/TheEmpireStrikesBack'', Yoda was created with puppets. In ''Film/AttackOfTheClones'', Yoda was created using 100% CGI and [[BrokenBase large portions of the fan base]] revolted, preferring Frank Oz's puppetry.
* ''Film/JurassicParkIII'''s raptors are brightly colored and frilled as a nod to the [[ScienceMarchesOn then-recent discovery that they had feathers]].
* By the third entry in Creator/PeterJackson's ''Film/TheLordOfTheRings'' series, he'd decided he wasn't a fan of the "witch noses" on certain orcs in the previous films. As a result, none of ''Return of the King'''s orcs sported long, pointy noses.
* Speaking of ''Return of the King'' adaptations, the glimpses of Legolas (who has been DemotedToExtra) in the Rankin & Bass version of ''WesternAnimation/TheReturnOfTheKing'' reveals an appearance retcon for the Elves compared to their appearance in ''WesternAnimation/TheHobbit''.


[[folder: Live Action TV ]]

* In ''Series/DoctorWho'':
** The original Daleks were clunky and, because they were mounted on tricycles, had difficulty with rough terrain. [[WeaksauceWeakness And stairs? Forget about it.]] [[spoiler: Until their very last appearance, anyway - but they couldn't fire at the same time until the new series.]] CGI allows the new series to feature flying Daleks who are capable of traversing stairs and ''interstellar space'' without trouble. Heck of an upgrade there.
** The Cybermen are famous for their repeated redesigns, which are fairly plausible in a species whose whole concept is ruthless self-augmentation. The major shifts are from the original "Tenth Planet" look with visible human body parts to the all-metal appearance of their second story "The Moonbase"; the shift to the "square-headed" silhouette in "The Invasion"; and the "baggy" eighties look from "Earthshock". But practically every story saw some tweaking to the design. The 21st-century series introduced another, even more robot-like look, and there was then a further redesign in the Moffat era to remove the "Cybus" branding that marked the Davies-era Cybermen as alternate-universe.
** Another ''Series/DoctorWho'' example: the Macra. Old series Macra look like [[http://i133.photobucket.com/albums/q55/ashtonlamont/mo_ma01_Macra_400.jpg this]]. New series Macra look like [[http://www.sylvestermccoy.com/newdoctorwho/gridlock/macra.jpg this]].
** The Silurians in the old series were done with rather clunky (and practically immobile) masks. The new ones are still created with makeup, but it's far more sophisticated and lifelike. However, the old ones were more ''alien'', featuring sucker-like mouths and three eyes. The new ones look more like green, scaly humans. This is acknowledged in-show as being different subspecies.
* In ''Series/BuffyTheVampireSlayer'', Oz's wolf form went from an animatronic to a much sleeker full-body skunk-wolf suit.
* The Klingons in the original ''Series/{{Star Trek|The Original Series}}'' series were basically [[UnfortunateImplications swarthy]] HumanAliens, but advances in make-up technology allowed them to become one of the best (and most believable) examples of RubberForeheadAliens. This example is notable in that GeneRoddenberry always claimed that the "new" Klingons were how they would have looked back in the 1960s if it had been possible at the time - he considered the new Klingon look to be how the old ones ''always'' did but [[LiteraryAgentHypothesis there just wasn't the budget to show it]]. (The original Trek often didn't have the budget even when it had the means. Why'd the old-school Romulans wear helmets? Easier than making custom pointy ears for everyone - which is also why several Vulcans wore the same helmets in "Amok Time"!) In-universe, the difference didn't exist until attention was called to it in an episode where the Series/StarTrekDeepSpaceNine crew went to the past. Then ''Series/StarTrekEnterprise'' comes along, with pre-TOS Klingons looking like the "new" ones! Yes, we ''do'' at long last get an explanation. None for Romulans (see below) though.
** It's worth pointing out that Worf's make-up alone improved significantly after the first season or two.
*** Both the Worf and Data makeups not only got better looking as the series progressed, they also became substantially quicker. Everyone was happier with the later makeup call for the two characters.
** ''Trek'''s Borg also received an upgrade in ''Film/StarTrekFirstContact'', losing the chalk-white skin in favor of glistening, apparently decaying flesh. They were given more implants on their bodies, and their ships were redesigned.
*** They also got a major design change between their first and second appearances. The second features a much more modular design to how the prosthetics were done, allowing more drones to be made up than the individual custom jobs used in the first appearance. The chalk-white skin was largely to save on labor in makeup, and techniques using quick airbrushing allowed the hard bits (like deeply shadowed eyes) to be done fast by a small number of highly trained makeup people after more generally trained ones did the bulk of it, again so that more drones could be made up.
** Romulans had the same make-up as Vulcans in TOS and some early TNG. In later seasons of TNG and all following series, they have a distinctive V-shaped ridge on their foreheads. However it seems that this retcon did not apply to all: there are later examples of Vulcans and Romulans passing as each other, suggesting there are minorities among both who look like the other.
*** In the new movie series - which ''isn't'' a {{Reboot}} ([[spoiler: villains from the TrekVerse as we know it ''changed history.'' It's not out of continuity any more than the last two seasons of ''Series/{{Eureka}}.'']]) ''all'' the Romulans we see are smooth-headed. The Klingons look completely different from any previous version as well.


[[folder: Video Games ]]

* The Covenant from the ''Franchise/{{Halo}}'' series have become more life-like and more scary-looking as computer animation technology has improved. Elites became stouter with more practical looking armor, Grunts more reptilian and red-eyed, and Brutes from hairy unarmored giants to weaker, armored, and shaven fellows. Their designs most deviated in ''VideoGame/HaloReach'', where the Elites' armor became very ornate and alien while the Brutes turned more ape-like, though still shaven.
* ''VideoGame/DragonAgeII'''s qunari now sport horns in order to differentiate them from the other races. The official explanation as to why the qunari seen in ''Origins'' don't have horns is that the qunari who are naturally born hornless, such as Sten and the members of his squad, are considered special and are given special tasks, such as scouting foreign lands, while the other qunari seen in ''Origins'' are [[DefectorFromDecadence Tal-Vashoth]] mercenaries who typically remove their horns when they leave the qunari.
** The hurlocks have also changed, appearing a few shades lighter, smoother-skinned, and with blunter teeth in the sequel.
* In the first ''{{VideoGame/Metroid}}'', due to graphical limitations, Kraid and Ridley are both the same size as Samus. By the time ''Super Metroid'' came around, Kraid was two rooms high, and Ridley was at least three times the size of Samus. ''Zero Mission'' retcons the ''Super'' design into canon.
** ''VideoGame/SuperMetroid'' also adds a "fake Kraid" that's slightly taller than Samus and much easier to kill outside of the real Kraid's room: this is both a reference to the size difference in the earlier games as well as the fact that the NES game had multiple Kraids, but only one of them was the real one.
** Throughout the ''Videogame/MetroidPrime'' series, the Space Pirate models vary greatly, gaining a separating lower jaw and going from two to four eyes. Partially justified due to the fact the Pirates are genetically altering their troops (with varying levels of success) to enable them to conquer the galaxy.
* ''Deus Ex: Human Revolution'', more than 10 years since the original ''Deus Ex'', has mechanical augmentations that are significantly more advanced and useful than the un-lifelike ones in ''Deus Ex''. The excuse is that this is right before a great collapse which occurs prior to the beginning of ''Deus Ex'' and before the rise of nano augmentations.
* Practically every memorable demon in the ''VideoGame/{{Doom}}'' series was completely redesigned for ''Doom3''. Most of these redesigns made the demons appear much scarier and more formidable opponents for the player. The original imp, for example, was a large, brown creature with spikes on its shoulders that would slowly advance towards the player while hurling fireballs at them. The new imp is a slimmer grey creature with no spikes and ten eyes on its head that is capable of climbing walls and has incredible jumping ability that allows it to clear the distance across an entire room in a single leap and generally attacks with a much more aggressive style.
* ''Franchise/TheElderScrolls'' series has surprisingly averted this for the most part, despite major overhauls to the graphics with each new game release. Most of the races and creatures that appear in each game have kept the same look, with only improvements in the ''quality'' of their appearance, not to the appearance itself. One area where it has been played entirely straight has been with the [[LizardFolk Argonian]] race. [[http://www.uesp.net/wiki/Arena:Argonian#Argonian Arena]] displayed them as gray skinned humanoids. Two games later, [[http://www.uesp.net/wiki/File:MW-npc-Big_Head.jpg Morrowind]] turned them into bird-legged, iguana-looking people. [[http://www.uesp.net/wiki/File:OB-npc-Amusei.jpg Oblivion]] returned them to more traditionally bipedal dinosaur-looking people. Finally, [[http://www.uesp.net/wiki/File:SR-race-Argonian.jpg Skyrim]] has them looking like, well, traditionally bipedal iguana-looking people (they use the same model as other races, apart from the lizard head and tail). This evolution is ostensibly justified in-universe by the fact the Argonians worship the "Hist," a race of sentient trees in their homeland of Argonia (or "Black Marsh"). Hatchling Argonians drink the sap from the Hist that changes them physically. After the events of the [[VideoGame/TheElderScrollsIVOblivion Oblivion Crisis]], it is believed that the Hist have been strengthening the Argonians, turning them into more formidable warriors over time.
** This possible justification is backed up by the fact that the Khajiit, who otherwise had the same development as the Argonians (with cats instead of lizards) actually ''did'' get a more-or-less official explanation involving physical differences between breeds (each individual's appearance is based on the phases of the [[AlienSky moons]] under which they are born).