Kryptos' appearance is similar to Bill, as Kryptos is also a floating geometric shape with black limbs. Like Bill, Kryptos is based on the symbol of a secret society, in this case, the masonic compass. It is a grey-navy colored rhombus. The top perimeter of its shape resembles a compass, with a functioning eye at the turning point, and the bottom perimeter resembles a square ruler. Additionally, Kryptos has a large wide mouth with buck teeth, wears black gloves, and has a small light blue aura.
Eons before the events of the series, Kryptos indulged in criminal activities before being called together by Bill Cipher, along with 8 Ball, Amorphous Shape, Hectorgon, Keyhole, Teeth, Paci-Fire, Pyronica, Lava Lamp Shaped Creature, and Xanthar.
In "Weirdmageddon Part 1", during the cold open, Bill introduces Kryptos with the rest of his friends to the residents of Gravity Falls. Afterwards, on Main Street, Kryptos and the others watch Bill turn Ford into a golden statue and taunt Dipper before burning the journals. Later in the episode, Kryptos is seen playing "Spin the Person" and enjoying the "V.I.P." party Bill is having at the Fearamid until Time Baby and the Time Police crash the party. To the beings' delight, Bill vaporizes Time Baby and his squadron. The party then continues as Kryptos and the other beings rejoice over Time Baby's presumed death.
In "Weirdmageddon 2: Escape From Reality", Kryptos and the rest of Bill's minions attempt to leave Gravity Falls to spread their chaos worldwide, only to be stopped by an invisible barrier around the town. He is later seen wearing a sling, meaning he broke his arm during the collision.
In "Weirdmageddon 3: Take Back The Falls", Kryptos participates in the battle against the Shacktron. Following Bill's defeat, he is sucked back to the Nightmare Realm along with his comrades.
- Due to his appearance, it was speculated that Kryptos is also a Dream Demon like Bill.