Bill Cipher is a fictional character and the main antagonist in the animated television series "Gravity Falls." The character was created by Alex Hirsch, the creator of the show.
According to Hirsch, Bill Cipher is a demon from another dimension who is able to manipulate reality and bend the laws of physics. He is described as being a powerful and malevolent being who is driven by a desire for power and chaos. He is also described as being highly intelligent and charismatic, able to manipulate and deceive those around him to achieve his goals.
In the show, Bill Cipher's main goal is to open a portal to his own dimension, allowing him to take over the world and gain ultimate power. He does this by using a variety of schemes and manipulations to corrupt and control the characters in the show, ultimately leading to a final confrontation with the main characters.
It's also said that Bill Cipher is a representation of the negative aspects of human nature, specifically greed and desire for power. He is also shown to have an intense desire to know and understand the mysteries of the universe, which is one of the reasons he became a demon.
In summary, Bill Cipher is a powerful, malevolent demon from another dimension, who is driven by his desire for power and chaos, his intelligence and charisma allow him to manipulate and deceive those around him to achieve his ultimate goal of opening a portal to his dimension and taking over the world.