When the puppets start talking to you, that means it’s time to stop,” says Michael King, the current operator of the Puppet Bike, a North Side curiosity that’s evolved into a Chicago street performance staple. I duck under a ragged cloth and enter the back of the miniature portable theater, parked this day on North Michigan Avenue. “Remember, it’s your show. You can do whatever you like. No pressure.”

He reaches inside the paint-splattered box and pushes a bright green button that controls the battery-powered stereo system. A boogie-woogie blues song blasts from the speakers, and suddenly a dozen tourists stop in their tracks and stare at the empty stage. Each gives a look that says, Entertain me. I stand paralyzed inside this vertical coffin-like structure, gazing anonymously from behind a black mesh curtain.

“You’ve got customers, bro,” King says. I jam my hands into two puppets—a smirking fox and a wobbly-headed bear—and bop them around in unison. Within minutes, pain pulses through my forearms. Then my index finger breaks through a hole near the bear’s neck. I fear I’ve already ruined the illusion—I may as well climb out and tell the youngsters there’s no such thing as Santa Claus.

Thankfully, I manage to conceal the stray appendage and, quite possibly, salvage the childhoods of the three giggling toddlers spellbound by my dancing animals. The song’s piano chords pick up momentum, and the furry critters on my hands begin bobbing in sync with the music. I make the puppets turn and look at each other and then back at the crowd.

“Congratulations,” King says, peeking backstage. “You are now a professional puppeteer.”

Equal parts creepy and charming, this magical mobile theater, known for its eclectic soundtrack and cuddly cast of hollow Steiff animals, celebrated a decade on the streets in 2014. Inventor and Chicago Heights native Jason Trusty designed it as a coffee bike. But when he found out that city regulations required his roaming java shop to have access to a commercial kitchen, he shifted gears. Inspired by a puppet show he saw in Colorado, he created an entertainment experience like no other. (Trusty says that, to his knowledge, his puppet bike is the only one in existence.) He used to man the bike himself, performing for tips stuffed in the glass box hitched to the front of the structure. But in recent years, he has entrusted a small group of subcontractors (who pay him a cut of their takings) to uphold his theatrical vision. I’d always wondered what it would be like to bring the Puppet Bike’s unique brand of joy to the world. When I heard that Trusty allows guest performers, I volunteered.

I meet King, Trusty’s main proxy, in front of the Wrigley Building. Trusty’s theater is called the Puppet Bike, but these days, the Worksman cargo cycle is far from roadworthy. In fact, the battered state of the top-heavy 400-pound contraption precludes it from being safely ridden more than a few blocks, so two other cyclists must tow it on long treks. The frame is rusty and the theater box weathered and tagged with graffiti. Duct tape holds the seat together. Most of the eight vintage puppets are in tatters. The box’s interior, with its floating disco ball, funky aroma like sweaty gloves, and floor full of dollar bills, resembles the world’s smallest strip club.

But the grubbiness doesn’t diminish the good vibes the Puppet Bike brings to the audiences, or operators, who fall under its spell. “Sometimes I make $50 an hour. Other times I make nothing,” explains King, 50, a gregarious former ski instructor with long gray hair and a New Age vibe. The Art Institute and the Chicago Theatre are among his preferred spots, as culture vultures tend to be good tippers.

Most of the job is fairly intuitive—the cute puppets and feel-good music do the heavy lifting—but as with most things in life, I find that the more I put into my routine, the more I get out of it. “Anyone can sustain a performance,” Trusty assured me when I called to confess my pregame jitters a few days before my guest stint. For King, his routines change based on his mood. “Feel free to switch the puppets whenever you want,” he advised. “Sometimes I’ll use two puppets, other times only one. The only rule is, try not to have the kids see you when you get in and out [of the box].”

The Bing Crosby classic “Swinging on a Star” comes on, and I’m inspired to grab a turtle puppet and have him lip-synch the words. For the first few stanzas, I’m not sure the audience realizes I’m doing this, but when I have the little green guy dramatically hold the last note of the line “Or would you rather be a fish?” resounding laughter affirms my artistic choice.

Soon the turtle is dancing a do-si-do with a one-eyed dog to a twangy tune, and the crowd—kids and adults alike—claps along. “Look, they’re dancing,” I hear a 30-something woman tell a six-year-old girl with a ponytail. “Is somebody in there?” the girl asks, and I hope that she believes the answer is no.

Next I see a boy in a stroller, and I wave at him with the dog’s tiny paw. His mom stops, and for the next three minutes, the jean-jacketed tyke stares slack-jawed at my show, which now includes the Slide (where both puppets glide across the stage together) and the puppets giving each other a series of high-fives. I’m not sure whether I made the kid’s day or gave him nightmares for a week. Either way, I left an impression.

I’m in a serious groove and having so much fun that I lose track of time. I’ve been in the Puppet Bike for more than an hour at this point, and with the exception of two rascally preteens who thought it was hilarious to violently kick the box, I’m treated with nothing but respect. There’s $18 in the tip box, which King insists I keep. (I count my crumpled earnings on the el ride home, like a real street performer.)

Finally, King peeks backstage and asks me if I’ve had enough. “Just one more song,” I tell him. A rocking blues number kicks in, and I push the volume button up a few notches. All around the Puppet Bike, the sights and sounds of the city intensify: Sirens blare. A white-gowned bride and her wedding party walk by and pose for pictures near the bridge. A protest happens across the street.

But for now, all eyes are on an alligator playing air guitar.