Lyzz Donelson lives in a quiet neighborhood in Southwest Austin. Occasionally, she hears the rumble of a motorcycle with an unusual rider.

“He’s just this really interesting character that drives through our neighborhood periodically," she says, "and he’s wearing the most outrageous outfits."

She really does mean outrageous.

“I’ve seen one where he’s wearing pool inflatables, like pool noodles and a giant inflatable turtle,” Donelson says. "I’ve seen one where he’s wearing a whole bunch of loaves of bread.”

So she asked our "Hi, Who Are You?" project to investigate: "Who and why?!"

The only constants in this mystery rider’s gear are his helmet, his 2003 Kawasaki Ninja and his high-top sneakers – yellow and black to match the bike.

Donelson isn't the only one who has seen him.

“Whenever he comes through the neighborhood, we all kinda shoot messages to each other, ‘What gives with this guy?’” she says.

Are you Bigfoot? Do you know Bigfoot? Let us know. Please. Seriously. Please.

What does give with this guy?

It seems no one really knows. But there are other sightings. There are Reddit posts. He followed a Google Street View car last year, so there is photographic evidence of his existence.

Amelia Harnagel has seen the masked rider here and there for the last two years. Her coworkers in Southwest Austin have kept something of a log.

“We work in an open office and most of our desks are somewhere near a window,” she says. "It’s a very loud motorcycle and somebody caught him doing a wheelie, and then the costumes grew ever more elaborate over time, and there’s no way to really miss him.”

She offers the same description as others: “Guy on a yellow motorcycle, riding by with various pool toys attached to himself, sometimes an inflatable suit,” she says. "There have been tutus. [He does] wheelies up and down the street.”

Harnagel offered me a bigger footprint to look for as we tracked this motorcycle Bigfoot.

“Up and down Southwest Parkway,” she says. "Up and down William Cannon, people have seen him. One person said they saw him off 290. I’ve never seen him that far. There’s even a Reddit post, somebody saw him, trying to track down who he was.”

With no name or address — and only a general area of Austin to look in — I went to look for him. It was like looking for a needle in a haystack – only that needle was strapped to a flamingo or an inflatable turtle or beach balls.

I spent weeks looking for him, and yet, nothing. That made me wonder: Does he really want to be found?

Then one day, there he was: turtle, beach balls, yellow kicks and all.

I pulled up next to him, but he just stared ahead, not moving a muscle.

I rolled down the window: "Excuse me! A lot of people of Austin want to know about you. Like, who are you? What gives? And why?"

He ignored me and pulled away.

Thus began the most thrilling car chase of my journalism career: a seemingly endless series of U-turns, hitting speeds in the high teens as we covered the same 400 yards in front of and then into an apartment complex. A few U-turns later, though, and he was out of sight. Vanished.

Like Bigfoot or even Batman, he doesn’t want us to know who he is or why he does what he does. And maybe we’re better off not knowing who’s beneath that helmet and those nonregulation airbags.

“It looks like he’s doing what he needs to do to be safe himself," Donelson says. "Honestly, I think he’s doing it just to put smiles on people’s faces, and I don’t have any problem with that.”

Got a tip? Email jmaas@kut.org or follow him on Twitter @maasdinero

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