Jaimie Mantzel takes self-reliance very, very seriously. The reclusive inventor constructed a workshop from scratch in the rugged backwoods of Vermont, cutting logs into broad boards with a homemade band saw. The purpose of that workshop? To build—on his own—a 12-foot-high spiderlike walking robot capable of carrying a human pilot. It’s a monstrosity Mantzel is creating out of equal parts metal and passion: Every runner, joint, and gear will be shaped by hand.

Mantzel has documented his project on YouTube, garnering more than 2 million views. The first video showed a toy-size prototype scurrying across the floor. The latest shows a towering monster. Since the hexapod design is basically a round body bristling with appendages, turning is a breeze: The control platform in the center will simply rotate above the legs—wherever it is facing is the new forward.

After more than three years of toil, Mantzel is still trying to get the bot up and walking. “Honestly, there’s no way in hell I’m getting on that thing till it’s well tested; it’s kinda scary,” he admits. At first it will be six-legged baby steps, directed by remote control. If it looks stable, he’ll climb aboard. Mantzel envisions the contraption eventually pulling lumber up the muddy track to his house—a handmade dome structure, natch.

Whether or not he turns it into a cargo transporter, Mantzel’s dreambot is making waves. A British toy manufacturer that saw his videos is now planning to put bite-size versions on store shelves. When the Giant Robot Project is complete, he says, he’ll go lie on his trampoline and dream up another ambitious endeavor. He has no specific plan yet, but he does have a working title: “Project Bite Off More Than I Can Chew.”