James Moriarty

"He is a man of good birth and excellent education, endowed by nature with a phenomenal mathematical faculty. At the age of twenty-one he wrote A Treatise on the Binomial Theorem, which has had a European vogue. On the strength of it he won the mathematical chair at one of our smaller universities, and had, to all appearances, a most brilliant career before him. But the man had hereditary tendencies of the most diabolical kind. A criminal strain ran in his blood, which, instead of being modified, was increased and rendered infinitely more dangerous by his extraordinary mental powers. Dark rumors gathered round him in the University town, and eventually he was compelled to resign his chair and come down to London. He is the Napoleon of Crime, Watson, the organizer of half that is evil and nearly all that is undetected in this great city..."

- Sherlock Holmes about Professor Moriarty in "The Final Problem".

Professor James Moriarty is the archenemy of Sherlock Holmes and is often considered one of the first supervillains in fiction - he appeared in only two novels and despite rarely encountering Holmes personally he is considered the main antagonist of the entire Sherlock Holmes series and is famously described as the "Napoleon of Crime".

History
Professor Moriarty is a criminal genius equal to Holmes in brilliance and was famous for being the villain that Sherlock Holmes fought and apparently fell to his doom with in The Final Problem - however due to a large public outlash Arthur Conan Doyle was forced to retcon these events so that both Holmes and Moriarty did not die as was originally planned but rather miraculously survived so that the series could continue.

Moriarty is mentioned but not seen in the novella The Valley of Fear, which is set before "The Final Problem." Here he is depicted as running a "criminal consulting agency," which liaises with various criminal organizations. Moriarty arranges the death of John Douglas, a former Pinkerton detective, as a favor for the Vermissa Valley Gang, a group of corrupt union officials who had been arrested by Douglas. Moriarty's men killed Douglas in spite of Holmes's attempt to save him, an act which puts Holmes forever at odds with Moriarty.

It's also depicted that he has obsession for technology. In the League of Extraordinary Gentlemen, he tricks the league and builds a war airship using the technology he got from his enemies, like Fu Manchu for example. He also brings with him a specialy designed Air Rifle that is disguised as a cane and is perfect for sniping.

Sherlock Holmes: A Game of Shadows
Moriarty also appears in the 2011 movie Sherlock Holmes: A Game of Shadows. Here he serves as the main antagonist of the movie. His version, complete with beard, bears a strong resemblance to purported Moriarty inspiration Adam Worth. During the film he attempts to provoke a war using advanced weaponry that he has developed while sending an assassin into a crucial conference using an early form of plastic surgery. With Watson having deduced his assassin's identity while Moriarty is occupied in a chess game with Holmes, Moriarty and Holmes clash, with the fight ending as Holmes pulls Moriarty over the edge of a balcony into a waterfall, knowing that he cannot defeat Moriarty in a direct fight due to a recent injury and wanting to protect Watson from Moriarty's revenge (Although Holmes is later revealed to have survived). Moriarty seems to have great abilities in the German language, his minions are germans and he sings the German song "Die Forelle" by Franz Schubert while torturing Holmes.

Sherlock (TV series)
Moriarty is also a recurring villain in the BBC update, portrayed by Andrew Scott. Here, he is a consulting criminal, paralleling Sherlock's role (Benedict Cumberbatch) as a consulting detective, assisting various other crooks by sponsoring, offering advice, or generally scheming. We first hear of him in "A Study in Pink", when Sherlock tortures his name out of the dying serial killer, and smuggler Shan talks with him online in "The Blind Banker" before she is assassinated by one of his operatives. He finally appears in "The Great Game" as "Jim from IT" and Molly's boyfriend, while in secret, he places hostages in suicide bomber vests, forcing Sherlock to solve certain mysteries within a time limit. Near the climax, he kidnaps John Watson and uses him as a hostage in the pool confrontation, telling Sherlock that he will "burn the heart out of [him]". The episode ends on a cliffhanger, only resolved when Moriarty receives a call from Irene Adler ("A Scandal in Belgravia").

In the second season, Moriarty advises Adler in how to deal with Sherlock and his brother Mycroft, with his only compensation being the chance to cause more trouble. He later appears at the end of "The Hounds of Baskerville", arrested and later released by Mycroft for unknown reasons. In his last episode, "The Reichenbach Fall", he allows himself to be arrested after simultaneously breaking into the Tower of London, opening the Bank of England's vault, and unlocking the cells in Pentonville Prison. He stands trial, but is later released after threatening the jury, and later pays Sherlock a visit, claiming that he owes him.

Moriarty then sets about ruining Sherlock's reputation, first by abducting the children of the British Ambassador to the US and traumatizing the girl to make her terrified of Sherlock, making it seem like he staged the kidnapping, along with all the other crimes he'd solved. He then sets himself up as Richard Brook, an actor that Sherlock supposedly paid to be Moriarty, feeding information Mycroft gave him during interrogations to a journalist whom Sherlock had scorned to create a fake exposé.

With no choice left, Sherlock stages a final meeting on the roof of St. Bartholomew's Hospital to discuss the solution to their "final problem". There, Moriarty tells him that there was no key, simply bribery, and that Sherlock must commit suicide, otherwise his assassins will kill John, Mrs. Hudson, and Lestrade. When Sherlock realizes that Moriarty must have a failsalfe to call his men off, he commits suicide, ensuring that he has no choice. (This ultimately fails, as Sherlock somehow manages to survive his apparent suicide.)

The League of Extraordinary Gentlemen
In Alan Moore's series The League of Extraordinary Gentlemen, Moriarty serves as the villain of Volume 1 where he deceives the League through Campion Bond into stealing the Cavorite that he uses to power his great warship. He engages The Doctor (Dr. Fu Manchu) in a sky battle over Limehouse. He is foiled when Murray smashes the container that holds the Cavorite which starts to float towards the atmosphere. Refusing to lose such a potent part of his plan, Moriarty clings to the Cavorite and subsequently drifts into outer space. In a later volume Century: 1910, he is found frozen solid in space while still clinging to the Cavorite.

Tom and Jerry meet Sherlock Holmes
In this cartoon movie, Moriarty is behind some diamond thefts which are done by three cats. When Tom, Jerry, Tuffy and Sherlock Holmes' client Red are following the cats while Holmes and Watson follow false clues, Red tries to hide herself and the others at her boyfriend's house. This boyfriend actually turns out to be Moriarty, who waited for Red who got the diamond the cats have just stolen. Moriarty explains his plan: using all the mirrors placed in London, he uses the diamonds for a laser canon to burn a whole into the Tower, planning to steal the juwels. After stealing the juwels and being followed by Holmes and Watson, Moriarty finally falls into the Themse, then he's arrested along with the cats by Droopy. Like in A Game of Shadows, Moriarty's got a beard in this movie.

The Real Ghostbusters
Moriarty appeared in an episode of The Real Ghostbusters "Elementary, My Dear Winstin"

Professor Moriarty was once an academic genius who resigned from his position at a college. He relocated to London and became a criminal mastermind responsible for at least half the crime in the city. Moriarty met his end when he and the titular detective fell to each other's deaths in a battle at Reichenbach Falls, Switzerland (though it was later revealed that Sherlock actually survived). Even though none of the characters in the Sir Arthur Conan Doyle novels were real, many fans believed them to be real, which caused ghostly versions of them to manifest. James Moriarty's ghost went to New York with the Hound of the Baskervilles in search of evil energy, which would enable him to solidify into a real person.

Moriarty went to the Containment Unit and attempted to open it to absorb the evil energy of the ghosts imprisoned within it, but he retreated when he heard the Ghostbusters coming. He then went on to absorb evil energy from various items often associated with evil, such as weapons at the Museum of Crime uptown and crime novels at theNew York City Public Library. He then decided to return to the Firehouse and succeed where he had failed. He opened the Unit and began to absorb the evil energy, but was foiled because the Ghostbusters had also met Sherlock Holmes and John H. Watson's ghosts. Holmes went into the Unit with Moriarty, mirroring their climatic battle. Watson then went into the Unit with the two. Moriarty was last seen in the Containment Unit covering his ears as Holmes played the Ghostbusters theme song on his violin.