found some references in One Piece to the real world through all these years.
This is what I found:
Characters from other tales:
- Monkey D. Luffy characterized as Gokuh, being a "monkey" both in name and behavior.
- Usopp as Pinocchio.
- Usopp (in Kuro arc) also representing the tale of The Shepherd's boy and the Wolf.
- Captain Kuro as Freddy Krueger.
- Sanji is "the invisible man". Although not literally speaking like Absalom, but he is the one that is unnoticed most of the times by marines or enemies until the very end.
- He is not found and depicted by the Unluckies.
- He doesn't meet anyone in Little Garden.
- He doesn't meet Mr.2 at the Merry and because of that Crocodile has no clue of him existing even
after he's tricked by Sanji.
- He doesn't meet anyone from Bellamy's crew or Blackbeard's crew in Jaya.
- He's not seen with his crew in Water 7. Allowing him to sneak into the Umi Ressha and the CP9 not
caring him until he tricks them.
- Marine's photographer can't take a pic of him and his wanted poster doesn't ressembles him at all, keeping him invisible at the world's eyes.
- Sanji is also a reference to Dragon Ball's Super Saiyans. Hair bristles (except eyebrow cover) and flames cover his body as the Super saiyan's aura or enerfy radiance.
- First, he "goes super saiyan" only led by his rage. (At Thriller Bark when said Nami is still kept by
Absalom).
- After training, he "goes super saiyan" at will. (As when ending the fight with Wadatsumi).
- Dracule Mihawk is characterized as Count Dracula. By name and also by his "home" and boat, depicting him as a vampire.
- Chopper as Rudolph.
- Chopper as Abominable Snowman.
- Mr. 2 Bon Kure as Lloyd Christmas (fom Dumb and Dumber) for his looks and as "The Mask" (from The Mask) for his power and behavior. Both characters played by Jim Carrey.
- Crocodile as Captain Hook.
- Crocodile referencing T-1000 from Terminator 2, when shot at the head in Impel Down.
- Pell as Horus.
- Chaka as Anubis.
- Van Augur as Adolphus from the Story of Baron Munchausen.
- Jesus Burgess as Albrecht "strongest man in the world" also from the Story of Baron Munchausen.
- Doc Q as the Queen of Snow White.
- Doflamingo as Spiderman.
- Gan Fall as Don Quixote (from his own story).
- Franky as a mix between Popeye and Ace Ventura.
- Hildon (Zombie nº 21) as Hiruma from Eyeshield 21.
- Absalom as a beast from The Island of Doctor Moreau.
- Dr. Hogback as The Penguin from Batman.
- Ryuuma as himself from Oda's WANTED.
- Captain John as Captain Jonathan Flint from Treasure Island.
- Lola's Zombie as Peggy Muppets.
- Victoria Cindry (zombie) as Sally (from Nightmare before Christmas).
- Duval as "The man in the iron mask". (Obvious iron mask. He being some kind of "double" of another person).
- Peterman as (alternative) Robin Hood.
- Sentomaru as Kintaro.
- Boa Hancock is a reference to Medusa.
- Emporio Ivankov as Dr. Frank-N-Furter (from The Rocky Horror Picture Show).
- Inazuma as Edward Scissorhands.
- Inazuma as Cruela de Vil also.
- King Dew as He-man.
- A pirate from Whitebeard pirates ressembles Barret Wallace from Final Fantasy VII.
- Ace dies in a way similar to Gokuh dying for the first time.
- Sanjuan Wolf as Hagrid (from Harry Potter).
- Vasco Shot as Sloth (from The Goonies).
- Ame no Shilliew as General Washizaki.
- Panfleet Admiral Kong is modeled after Kongou Banchou.
- The past of Luffy, Ace and Sabo, a reference to Tekkonkinkreet.
- Sabo as Oliver Twist.
- His hat, one from Linda Perry (from 4 Non Blondes)
- Baron Tamago as a mix between Dr. Robotnik and the man from Monopoly.
- Baby 5, at least to me, totally looks like Babydoll (from Sucker Punch).
- Baby 5, in his torpede form, is a reference to Torpedo Girl (from Bobobo).
- Leo is modeled after Leo Messi (best soccer player). Maybe his crown unbends at the end of the summer depending on which country wins the World Cup...
- Wicca is a reference to WIlly wonKA.
- Sugar is a reference to Amélie Poulain.
Artists:
- Jango as Michael Jackson (hair style, moonwalk).
- Monkey D. Garp as Sean Connery
- Captain Bogard as Humphrey Bogart.
- Mr. 5 as Lenny Kravitz
- Lafitte as Iwatani Tokiko and Pinky and the killers.
- Donquixote Doflamingo as Michael Bolton dressed like Jean Michel Polnareff.
- Eneru as Eminem.
- Aokiji as Matsuda Yūsaku.
- Rob Lucci as Slash (from Guns'n'Roses)
- The unnamed CP9 from the past could be a reference to Brian May (from Queen).
- Brook as Jimmy Hendrix.
- Brook also as Michael Jackson. (Black man becoming white. Zombie. The 45º move.)
- Perona as Emillie Autumn.
- Killer as Guy-Manuel de Homem-Christo (from Daft Punk).
- Eustass Kid's crew as a reference to different styles of Heavy Metal music (one per crewmate). And also his ability to manipulate metal.
- Basil Hawkins as Jordison (from Slipknot).
- Kizaru as Tanaka Kunie.
- Although most surely this was not Oda's intentions, Jinbe very much resembles Spanish-gypsy artist Falete.
- Akainu as Sugawara Bunta.
- Makugai as Gérard Depardieu in his role as Porthos in The Man in the Iron Mask.
- This may be pure coincidence, but Shanks and Johnny Depp resemble each other.
- Fujitora as Katsu Shintaro.
Other character references:
- Shushu is modeled after Hachikō, the dog that waited for his dead owner everyday at Shibuya Station until he died too.
- Fishmen and merfolk play the role of black people. Notice that no character is black. Not even the ones with "afro hair".
- Blackbeard actually representing real life Balckbeard.
- The Gorosei members are modeled after some notorious people in history:
- One as Mikhail Gorbachev.
- One as Mahatma Gandhi.
- Foxy as Count Chocula.
- Vice-Admiral Yamakaji as Fidel Castro.
- Makro and his crew are a reference to the real life existence of black slave holders. Or any other example of someone enslaving his fellows.
- Trafalgar Law as Valentino Rossi aka "Il Dottore".
- Capone as reference to the Italian mafia.
- Magellan as Satan.
- Fisher Tiger as Che Guevara.
- Thunder Soldier is a reference to terrorist Guy Fawkes.
Culture:
- Arlong is a reference to Loan Sharks.
- Dorry and Brogy as the ogres from Naita Akaoni (The crying red ogre). Indeed, Brogy (the red ogre) is the one who cries as Dorry is still alive.
- Civil war is an episode of many and many nations all over the world, and it is the theme of Arabasta arc.
- American Colonial Wars (both in north america and in central and south america) are the theme for Skypiea's arc.
- The Davy Back Fight is reference to Davy Jones.
- The Admirals represent each a particular vision or feature of Justice:
- Aokiji represents the slow procedures justice (and burocracy in general) may take.
- Kizaru represents the corruption of justice. Chasing after something for unrighteous resons but
justifying it oficially as though it is a threat for people. Seen in his attitude of lying, saying that
something is terrifying and playing scared.
- Akainu represents the most strict and oppressing justice in which everything that could be seen as
a threat, a felony or a missbehavior must be punished. No excpetion.
- Fujitora represents the blind justice. Clear evidence is not enough. There must be some proof to
demonstrate guilt.
- Also, CP9 represents Machiavelli's most famous sentence "The goal justifies the means."
- Slavery is the theme for the Shabondy Arc.
- Jailers and chiefs in Impel Down are a referencte to the SS personal guard to Adolf Hitler.
- Hannyabal is another reference to ancient Egypt gods.
- Impel Down is based on Dante's representation of hell.
- Shi no kuni is a reference to the eruption of Mount Vesuvio at Pompeia. (Check for images of the victims).
Architectonics:
- Logue Town ressembles Torino (Italy) or at least has architectonics similar to those of Piemonte region. Torino is just an example I came up with.
- Whiskey Peak has architectonics of Caribbean small towns in the colonial period. Maybe due to the Grand Line representing The Caribbean Sea, and Whiskey Peak being the first island seen there.
- Arabasta represents the Ancient Egypt.
- Water 7 is modeled after Venezia.
- Amazon Lily is a reference to the village from The Adventures of Asterix.
- Dressrosa is modeled after Spain in many ways.
- Culture, including the corruption.
- The gladiators fights, they existed for long time while Spain was part of the Roman Empire.
- Now, gladiators fights evolved into "tauromaquia". Shows where many men humilliate, torture and
assassinate bulls. That is why there are fighting fish (being half bull half fish) at the colosseum.
- Violet outfit and first appearance are reference to "flamenco" music and dancing genre.
- Many buildings at the streets exist in Barcelona (dessigned by Antoni Gaudí).
- The most famous appeared being "Parc Güell", which is actually the giant plateau where the royal
palace is.
- Also appears "Puente Grande" from Málaga.
- And the Royal Palace is in fact "La Alhambra" from Granada.
There are lots more references in names of characters and locations. But listing that would be much harder
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There's more:
-Dr. Martin Luther King as Otohime and Fisher Tiger as Malcolm X (who advocated separation and whites as evil, then changed just before he died (after making a long trip to Mecca where he realized there were good white people, too), while MLK advocated peace and equality. Both were assassinated). Can't believe no one mentioned that.
-The trash sorters in Grey terminal are a reference to Smokey Mountain dump-slum in Manila, Philippines where 30,000 people live as trash pickers, frequently dying from mass fires.
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When Rayleigh blocks Kizaru on the archipelago, it is a direct reference to a scientific term known as Rayleigh scattering.
Another more recent scientific reference is when donquixote doflamingo blocks Fujitora's meteors, it refers to The ESA's preliminary design of a space mission named Don Quijote, that, if flown, would be the first intentional asteroid deflection mission ever designed.
(posts by Eric Ester Burgos & Jae Johnson & Two Cents @ 
