Hectorgon

 is a demon and an interdimensional criminal, from an unknown dimension, that appears during the events of Weirdmageddon.

Background
Eons before the events of the series Hectorgon indulged in criminal activities before being called together by Bill Cipher, along with 8 Ball, Amorphous Shape, Keyhole, Kryptos, Teeth, Pacifier, Pyronica, Teeth, and Xanthar.

Season 2
In Weirdmageddon Part 1," during the cold open, Bill introduces Hectorgon with the rest of his demon friends to the residents of Gravity Falls. Afterwards, on Main Street, Hectorgon and the other demons watch Bill turn Ford into a golden statue and taunt Dipper before burning the journals. Later, Hectorgon is seen playing "Spin the Person" at the "V.I.P." party Bill is having at the Fearamid, until a calcified statue of Lazy Susan points in the demon's direction and Pyronica happily swallows Hectorgon whole.

In "Weirdmageddon 2: Escape From Reality," Hectorgon and the rest of Bill's minions attempt to leave Gravity Falls and spread their chaos worldwide, but are stopped by an invisible barrier around the town.

While Weirdmageddon was being reversed in "Weirdmageddon 3: Take Back The Falls", he was sucked back to the nightmare realm.

Appearance
Hectorgon is a red hexagonal demon with arms, big tangerine lips, a mustache, a bowler hat with a gold rim (Light blue in this picture), and a light blue tie. Hectorgon has a small red aura.

Trivia

 * Hectorgon is Alex Hirsch's favorite demon.
 * This demon's name is a pun of the name, Hector, and the shape, hexagon.

Hectorgon