The Shapeshifter

Lore & Background

Decoded writing in the crashed spaceship reads "Specimen has escaped is changing forms", suggesting it escaped the ship and laid an egg on Earth that Ford found and raised. Journal 3 says Ford kept it as a test subject for his cryogenic freezer, grew fond of it and named it "Shifty", but froze it after it began attacking and impersonating Fiddleford to get the journals. Once free, it takes the shape of a man from a canned-beans advert, steals Journal 3 and tries to escape, until Dipper, Wendy, Soos and Mabel lock it back in its chamber.