Bill Cipher

Bill Cipher is a dream demon that can be released into a person's mind.

History
Bill, and the Eye of Providence he is based on, appear frequently in Gravity Falls. He is an unseen character who wrote the cryptograms in the online game Rumble's Revenge. His name and existence is deduced by taking all the capital letters in the cryptograms from Rumble's Revenge, forming the sentence: "MY NAME IS BILL."

A picture of Bill shows briefly at the end of the opening theme.

In "Dreamscaperers," Mabel and Soos witness Gideon summoning it in the forest. Later, Gideon releases it into Stan's mind where Dipper, Mabel, and Soos must chase it down. His entry in 2 makes not of his association with the glasses symbol. It also says, "This old triangular being has appeared in my dreams every night for weeks."

Appearance
He is a golden yellow triangle with a pyramid design, with an eye in the middle. In the theme song he has a hat on, a bow tie, and stick arms and legs.

Sightings
The following are sightings of Bill and the Eye of Providence:

Trivia

 * He is based off of the Eye of Providence, which is most commonly seen on the back of an US$1 bill.
 * A symbol on the rug of the Mystery Shack known as the "Eye of Providence" resembles Bill.
 * On the page about Bill in book 2, the -$12 bill says "Semper vigilantum," which in latin means "always watching."