Note that this is essentially definition of archetype/concept.
Supreme Con Man
The Cunning One
The One Who Lurks in The Shadows
User is (or can draw power from) a Trickster: a god, goddess, spirit, man, woman, or anthropomorphic animal who plays tricks or otherwise disobeys normal rules and conventional behavior. The Trickster openly questions and mocks authority, encourages impulse and enthusiasm, seeks out new ideas and experiences, destroys convention and complacency, and promotes chaos and unrest. At the same time, the trickster brings new knowledge, wisdom and many An Aesop. Even when punished horribly for their effrontery, indomitable spirit (or plain sheer foolishness) keeps them coming back for more.
Tricksters can be anything from gods of chaos, bedeviling heroes for a few laughs, to master manipulators who use cruel ploys and sadistic choices. They can also be heroes (or more likely Anti-Heroes) who make up for a lack of strength or bravery with manipulation, planning, or just plain cheating. The trickster is often a Master of Disguise and may have magical or super-powers.
In mythology and religion, the trickster deities breaks the rules of the gods or nature, sometimes maliciously but usually (albeit unintentionally) with ultimately positive effects. Often, the bending/breaking of rules takes the form of tricks or thievery. Tricksters can be cunning or foolish or both; they are often funny even when considered sacred or performing important cultural tasks.
The Trickster & His Brigade (Doctor Who/The Sarah Jane Adventures)
The Doctor (Doctor Who)
The Master (Doctor Who)
Bugs Bunny (Looney Tunes)
Lotso (Toy Story)
Discord (My Little Pony: Friendship is Magic)
Woody Woodpecker (Woody Woodpecker)
John Constantine (DC)
Mister Mxyzptlk (DC)
Flip (Little Nemo)
Impossible Man (Marvel)
Xelloss (The Slayers)
Naruto Uzumaki (Naruto)
Joseph Joestar (JoJo's Bizarre Adventure)
Gin Ichimaru (Bleach)
Sosuke Aizen (Bleach)
Flip (Little Nemo: Adventures in Slumberland)
Monkey D. Luffy (One Piece)
Jabra (One Piece)
Caesar Clown (One Piece)
Usopp (One Piece)
Donquixote Doflamingo (One Piece)
Teufel Diabolos (Senyu)
Queen of Maggots (The Cat Lady/Downfall Remake)
Hazama/Yuuki Terumi (BlazBlue)
Yukari Yakumo (Touhou Project)
Tewi Inaba (Touhou Project)
The Contessa (Sly Cooper)
Dr. M (Sly Cooper)
Cyrille Le Paradox (Sly Cooper)
Trickster (Valkyrie Crusade)
Loki (Valkyrie Crusade)
Puck (Valkyrie Crusade)
Erevan Ilesere (Forgotten Realms)
Jane Crocker (Homestuck); via spiral sucker
Jake English, Roxy Lalonde, Dirk Strider (Homestuck); via significant contact with other people in Trickster Mode
Carrotjuice (Channel Awesome)
Loki (Marvel) is the Norse God of Mischief
Naruto Uzumaki (Naruto) is able to use his skills in unique and confusing ways.
Obito Uchiha (Naruto) was so skilled in his acting, he was able to deceive almost everyone in the entire world that he is Madara Uchiha, down to his voice.
Lorenzo (American Dad!) made a deal with Roger Smith to teach him guitar lessons that will ensure his victory against Jamal at the cost of his soul...
...but Roger cunningly conned Jamal into covering the "price for [his guitar] lessons", saving Roger from Lorenzo's grasp at the cost of Jamal's soul.
Bugs Bunny (Looney Tunes) is perhaps one of the sneakiest characters in cartoon history.
Usopp (One Piece) is a skilled and experienced liar. His fighting style revolves mostly around outsmarting the opponent through clever tactics and trickery.
Mystique (Marvel) uses her shape-shifting powers to deceive people often.
Spider-Man (Marvel) often uses tricks to take out his rogues.
Aizen (Bleach) was able to fool the Soul Society for over a century.
While not the smartest guy around, Luffy (One Piece) can be sneaky and has some clever attacks.
Joker's (DC Comics) cunning is matched only by his sadism.
Loki (Norse Mythology) is the god of mischief.
The Contessa (Sly Cooper) was able to fool Interpol into sending her criminals who she then steals from.
Dr. M is a skilled manipulator, tricking Sly into leading him through the Cooper Vault via a tracer placed on his cane and planting doubt in Bentley's mind about his friendship with Sly.
Cyrille Le Paradox (Sly Cooper:Thieves in Time) was shown to be an adept manipulator, having been able to persuade El Jefe, Toothpick, Grizz, Penelope, and Ms. Decibel to join him, only to betray them all in the end.
Azula's (Avatar) intelligence made her very skillful in manipulating people.
Alejandro (Total Drama World Tour) is the most untrustworthy and manipulative player in Total Drama history.
Hazama/Yuuki Terumi (Blazblue) is known as the 'God of Trolling' because of his use of obnoxious and sarcastic remarks to either hurt people's feelings or manipulate their emotional responses in his favor.
Joseph Joestar (JoJo's Bizarre Adventure) from a young age, is considered a master trickster, able to outsmart a variety of opponents with dirty and unpredictable tactics, including beings that have lived tens of thousands of years.
Jabra (One Piece) has been known to trick people through convincing lies so he could attack them when their guard is down.
Trickster (Valkyrie Crusade) is a chaotic trickster goddess.
Loki (Valkyrie Crusade)
Carrotjuice (Channel Awesome) is a rabbit-like creature and a parody of Beetlejuice, taking the Nostalgia Critic's personal hard-drive and messing with him constantly.
Hisoka (HunterXHunter) is a deadly hunter with equal strengths in both physical and mental categories but his most deadly aspect is his unpredictable nature. He does things according to whether they will amuse him or not.
Xelloss (The Slayers) Sore wa Himitsu desu~! ("That is a secret~!")
The Trickster (Sarah Jane Adventures)
Puck (Valkyrie Crusade) is a trickster fairy.
Doflamingo (One Piece) used his Devil Fruit to overthrow King Riku and disgracing the Riku bloodline, making him look like a hero in front of Dressrosa.