Summerween Trickster

The Summerween Trickster is a large, dark, purple/grey monster with a yellow jack-o'-melon mask. He makes an appearance in "Summerween," in which he threatens to eat Dipper, Mabel, Grenda, and Candy, and the other kids of Gravity Falls if they don't acquire 500 candies in order to meet his quota for the night before the last jack-o'-melon's flame goes out.

History
The Summerween Trickster first appears by spying on Dipper as he discards of rejected "loser" candy from a nearby bush. At the front door of the Mystery Shack, Dipper insults the monster by repeatedly closing the door and refusing to give him the candy he desires. When Mabel willingly opens it and apologizes, the creature, disguised by a mask and coat, enters and threatens to devour Dipper, Mabel, Grenda, and Candy if they are unable to acquire 500 pieces of candy by the time of the last jack-o'-melon burning out; he then crawls over the roof out of sight. Dipper, who anticipated joining Wendy at a Summerween party, has no other choice but to join the others in trick-or-treating. When Dipper refuses to wear a costume and they get only one piece of candy, however, the Trickster reappears and frightens the gang.

The kids are eventually able to obtain enough pieces of candy, but when Dipper pushes the candy supply into a nearby bush as Wendy passes by, he later discovers that the candy had fallen into a river. The Summerween Trickster then finally confronts the children, upset to discover that the candy had been lost. He then attempts to devour the children, but is smashed apart by Soos in a pickup truck. Convinced that the monster is done for, they drive away with Soos, only for the pieces of the Trickster to reassemble into an even more hideous, malformed beast.

The gang crash into the Summerween Superstore and hide among the shelves, as the monster begins to search for them furiously. They then use costumes to disguise themselves in order to escape, but when Soos draws sound from an electronic laughing skull, he was devoured. The kids begin to use costume weapons to strike him repeatedly. The monster then grabs the children and reveals its true face and explains that he was made from discarded candies and planned to seek revenge from all the "loser" candy that had been ignored and discarded by the children of Gravity Falls. Soos (and Gordie) then emerge from the monster, bursting out from its body, and begin to feast on the beast's candy innards. The monster then cries in joy after finally being viewed as delicious, only by Soos.

Appearance
The Summerween Trickster first appears to be an unusually tall, extremely dark-skinned man with twig like arms and legs. In this form, he wore a patch-work suit jacket, a yellow mask of a smiling jack-o'-lantern face, and a shoddy hat similar in style to one often worn by Old Man McGucket. This form is eventually found to be a ruse however, as the Trickster sheds his disguise and reveals himself to be a creature made entirely of discarded and forgotten "Loser candy," such as black licorice or candy corn.

In this form, he can change shape at will, growing extra arms and legs to aid in mobility, and changing size as well. His face underneath the mask is composed of two mints for eyes, two rolls of a candy similar to Smarty's for eyebrows, a long piece of Licorice for a mouth, and candy corn for teeth. He was also seen to cry candy corn instead of tears.

Abilities
The Summerween Trickster is shown to be incredibly agile and quick, able to move both on two legs and all fours. When moving quadrepedally, it's motions are similar to those of a spider. It can also jump extremely high, able to reach the tops of buildings easily, and incredibly strong, able to lift people with a single hand and tear off car doors with relatively little effort.

Along with all of that, it can also reform if smashed to pieces, regenerate limbs, shape-shift (e.g. change size, grow extra limbs), and swallow an entire person. As if that wasn't enough, the Trickster also seems to possess other, more paranormal powers, such as being able to light a jack-o'-melon with a finger tip. It's presence also seems to cause strange events such as lights flickering and sudden, chilling winds to occur.

Trivia

 * The Summerween Trickster can be seen at 0:33 in the intro, in one of the photos, albeit with an orange skin color.
 * The Summerween Trickster's second form is an homage to No Face from the film Spirited Away.
 * In the promo for "Summerween," the Trickster is colored a much brighter purple than in the actual episode.
 * The Trickster is the cause of death for at least three teenagers: Jeffy Fresh, Byrone, and R-R-Rosie.

Quotes
"You must trick or treat... Or die!"

- Summerween Trickster