If you're being tailed by a bulbous, yellow stalker, it can mean one of two things: Either Donald Trump is off his meds, or you followed Mellow Mushroom on Twitter. The Atlanta-based pizza chain is returning the favor of a Twitter follow by sending its felt-covered hippie-shroom mascots to shadow some of its online followers in the physical world. Fitzgerald + Co. orchestrated the "Follow Us and We'll Follow You" campaign and contacted friends and family of the restaurant's recent social-media converts to coordinate the stalkings, which are captured in a series of YouTube clips. It's all here, from the faux horror-flick music to the groundbreaking use of the mushroom-cap cam to get the requisite "scary" shots from the stalker's POV. Some folks seem blithely oblivious to the beast, while others are fairly freaked out as they're stalked in shopping plazas, restaurants, parks and office lobbies. Adding a delicious element of claustrophobia, they're even followed into elevators. (I rode up to the sixth floor yesterday with a dude who wasn't bulbous or yellow, but man he smelled like fungus.) At one point, a guy in sunglasses turns and asks a big yellow mushroom, "What's the scoop?" I'll answer that: The notion of being stalked—either online or IRL, but especially when one follows the other—unsettles most of us on some level, allowing the campaign to successfully tread a fine line between goofy and edgy. Sure, those Sid and Marty Krofft-style dome-tops are probably harmless. Then again, they might kill you in horribly painful ways, especially if they've passed their sell-by date.