Mabel starts leaving handmade jewelry around their school, their neighborhood, the local grocery store. People who know her are afraid to touch them but strangers pick up these little wire and yarn doodads and find themselves having some very good luck.
There’s a rumor that that kid who always falls asleep in class couldn’t sleep at night because a ghost was haunting him. One night they find out that Dipper got in trouble for breaking into his house in the dead of night. That kid stops falling asleep in class.
On all their homework and tests, they leave behind red ink eyes crossed out with an X. One of Mabel’s classmates asked her why and she looked up front, at their Trigonometry teacher and said, just in case.
Dipper listens to a death metal band called Robbie V and the Tombstones. No one can find their songs anywhere, but if you ask he’s happy to lend you his CDs.
Mabel remembers everything, about everyone. She’s the only one who remembers the birthdays of the kids with no friends and she shares happy memories when her peers are upset about a grade or family stuff. She writes down little details in a pink glittery notebook, so that no one will ever forget.
Dipper and a group of his classmates went on a field trip in the woods. When Dipper disappeared for several hours, the teachers panicked, but he appeared at their bus a few hours later, having collected all the data he needed for his bio lab and toting a jar filled with multicolored moths. He’s banged up, but he doesn’t seem to notice. When someone asks where he got them, he says “Mothman” and doesn’t answer any more questions.
Mabel makes a tidy profit off of Mabel Juice during final exam season. Half their graduating class will swear by it all through high school even if it does taste terrible. (The arrest rate for stimulant drug use drops close to zero.)