Neil DeGrasse Tyson makes for some pretty fantastic TV. (It's why the man deserves an Emmy, for heaven's sake.) But if you haven't been watching Gravity Falls, he's the reason you should start. Last night, the country's most prominent scientist (sorry Bill Nye) guest-starred on the show's Halloween episode as Waddles the Pig, but only after he'd eaten a bowl of brain-enhancing goo. Hijinks ensue from there, and the show's already brilliant and nerdy sensibilities are only enhanced by Neil's presence. This is a show you need to get into.