Bigfoot

Bigfoot, also known as Sasquatch, is a beast shown in Gravity Falls' opening credits running and looking at the camera. It is an allusion to the famous film that allegedly contains footage of Bigfoot.

History
He appears in one frame in the opening credits. In "Tourist Trapped" and "Boss Mabel," it is shown that Grunkle Stan has made a "Sascrotch" a parody of Sasquatch wearing underwear, as one of the many hoaxed exhibits in the Mystery Shack.

Later in "Dreamscaperers," Bigfoot makes his first episode appearance in the series as an image of the creature flashes on Bill Cipher's body.

Appearance
The creature, has brown fur all over its body. The "Sascrotch" from "Tourist Trapped" and "Boss mabel," has brown fur, its ear, hands, feet,and face are green and it is wearing underwear.