Gobblewonker

The Gobblewonker is a legendary sea monster that is thought to live at the bottom of Lake Gravity Falls. In the episode, "The Legend of the Gobblewonker," Dipper and Mabel embark on a mission to get proof of the legendary sea monster that lives at the bottom of the local lake, to win a photo contest.

When Grunkle Stan takes Dipper and Mabel to the lake for some "family bonding time," Old Man McGucket starts running around the pier saying he had seen the Gobblewonker. It is later learned that the Gobblewonker is actually a robot, and Old Man McGucket likes to create extremely dangerous robots when he feels neglected. However, a real sea monster is shown at the bottom of the lake at the end of the episode. The Gobblewonker is a parody of the Loch Ness Monster.