1. The Zodiac Killer.

The Zodiac Killer was a strange serial killer from the 1960's and 70's. He murdered victims throughout Northern California. His letters used ciphers and only one has been truly solved.

2. Babushka Lady.

Babushka Lady is the nickname for a woman present during the assassination of JFK in Dallas. She gains her nickname from the scarf she wears.

3. Gil Perez.

Gil Perez was a 16th century soldier who belonged to the Filipino Guardia Civil and guarded the Governor General in Manila. It's said that he had the ability to teleport. This got him in some hot water.

4. Tank man.

Tank man was a man who stood in front of a column of tanks on June 5th, 1989 in Tiananmen Square. There is no reliable information about who he was.

5. Man in the iron mask.

The man in the iron mask was a prisoner arrested as Eustache Dauger in 1669. He was held in jail, including the Bastille, for 34 years. He died in 1703. It's claimed he is the older, illegitimate brother of Louis XIV.

6. Dan Cooper.

Dan Cooper is the name given to an unidentified man who hijacked a Boeing 727 in Oregon airspace in 1971. He then extorted a $200,000 ransom and parachuted to an unknown fate. The FBI never found him.

7. The Woman of the Seine.

L'Inconnue de la Seine was an unidentified young woman whose death mask has been a popular fixture on the walls of the homes of artists post 1900.

8. Umbrella man.

Umbrella Man, identified as Louie Steven Witt in 1978, was a name given to a man who appears in the Zapruder film of the JFK assassination.

9. Poe Toaster.

Poe Toaster is the name given to an unidentified person, possibly two people, who paid an annual tribute to Edgar Allen poe by visiting the cenotaph that marked his original grave in the early hours of January 19th.

10. Satoshi Nakamoto.

Satoshi Nakamoto is either a person or group behind the Bitcoin protocol and software, Bitcoin Core.