A quick note explaining this story's main character.

A girl named Connie finds herself in a clearing where she finds herself face to face with a statue of a creature with one eye. She decides to shake the hand of this strange statue unleashing a powerful demon back into Gravity Falls. But when this demon brings over a mutant turtle from New York City will things get more confusing for poor Connie?

A Gravity Falls TMNT 2012 Crossover