In "Weirdmageddon Part 1," during the cold open, Bill promptly summons the giant pyramid in order to establish his new found dominance over Gravity Falls. Later, Bill invites his demon friends to a "V.I.P" party in honor of them conquering Gravity Falls' dimension. However, during the festivities the Time Police along with its leader, Time Baby, crash the party stating that Bill's tampering with the town's dimension "could destroy the very fabric of existence." Despite their efforts, the squadron, including Time Baby, are instantly vaporized by Bill, leaving as the only survivors Time Baby (who according to the episode's cryptogram will regenerate in 1,000 years) and Blendin Blandin, who makes a narrow escape from the Fearamid.
In "Weirdmageddon 2: Escape From Reality," Bill is sitting on a throne made from townspeople turned to stone. He then announces his plan to spread weirdness across the globe. However, the plan is curtailed by an invisible barrier around Gravity Falls, to Bill's annoyance.
In "Weirdmageddon 3: Take Back The Falls," the Fearamid was broken into by the Shacktron so Dipper, Mabel and their friends could enter and rescue Ford from Bill's clutches. Later, after Bill's defeat, the Fearamid disintegrates into nothing.
It resembles a large dark red-brown pyramid with the top detached and multiple bricks and broken off pieces floating around it. From within the cracks, there is an orange-red glow which resembles lava. These lines flash neon colors to the beat of music as Bill and his friends party within. It hovers just below the rift where Bill and his minions first emerged.
The interior is black with neon, rainbow cracks around the bricks which also appear to flash in time with the music. There are stairs seemingly leading to nowhere, and a large, red stained-glass window which resembles an eye with a slit pupil(the last of which cannot be seen from the exterior). Bill's throne (made up of petrified humans) is also in the room, which sits on a dais that looks like a black and rainbow-lined pyramid with the top missing and two stairs lining the bottom. Most of the Fearamid is as seemingly made up of a series of twisting hallways and corridors. Curiously, the interior is not pyramid-shaped.
Inside the floating tip at the top of the Fearamid is a penthouse suite. It has furniture with upholstery made of human skin, a fireplace with a portrait of Bill wearing a crown hanging over the mantle, a demonic grandfather clock, a grand piano, and a large eye-shaped window. As it is at the very top of the Fearamid, all the walls are very visibly slanted and meeting at the very center of the ceiling.