Darlene is a spider disguised as a human female who lures men that visit her tourist attraction called Mystery Mountain and traps them in cocoons to eat them. She is the main antagonist of the episode.
The beautiful Darlene seduces Dipper’s great uncle ‘Grunkle’ Stan, while secretly hating him. She lures him to a secluded place in Mystery Mountain, captures him and prepares to eat him alive. However, he is freed by Dipper and his friends. They enter a kiosk (I don’t know what it’s called) which takes them over the sky, and the villainous femme fatale chases them. There, Dipper’s ex pulls a lever that sends the kiosk falling down from the sky, Darlene along with it. There, she is trapped underneath the boot of a gian statue. Darlene tries to seduce Grunkle Stan again by shifting into her human form, but when He gets up close She attempts to eat him. Darlene smugly states that she’ll never run out of prey because there will always be foolish men like him. She is presumably freed later by a gullible man (offscreen.)